herokuでデプロイしたらエラーになってしまう

前提

rails tutorialで学習中です。
cloud9のターミナルで git push heroku master した後、herokuでデプロイしてもWebページには

Application error
An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command
heroku logs --tail

とエラーが表示されてしまいます。

実現したいこと

エラーの解決

発生している問題・エラーメッセージ

$heroku logs --tail
2022-09-27T11:19:25.429742+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=fathomless-shore-68344.herokuapp.com request_id=80f4a59e-ab4a-485d-990f-2bad86af7a1f fwd="156.146.35.170" dyno= connect= service= status=503 bytes= protocol=https
2022-09-27T11:28:53.686261+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=fathomless-shore-68344.herokuapp.com request_id=d1178c52-40cf-45ca-aadc-162171111f49 fwd="156.146.35.170" dyno= connect= service= status=503 bytes= protocol=https
2022-09-27T11:28:54.530109+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=fathomless-shore-68344.herokuapp.com request_id=6589b966-65cd-4c66-9294-01d90944585b fwd="156.146.35.170" dyno= connect= service= status=503 bytes= protocol=https

※字数制限の為割愛


2022-09-27T11:39:03.981726+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=fathomless-shore-68344.herokuapp.com request_id=c7dea03d-6485-4ef9-a88e-5a1820eacd94 fwd="156.146.35.170" dyno= connect= service= status=503 bytes= protocol=https
2022-09-27T15:42:39.579344+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-27T15:42:42.863340+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-27T15:42:44.356170+00:00 app[web.1]: npm ERR! missing script: start
2022-09-27T15:42:44.362295+00:00 app[web.1]: 
2022-09-27T15:42:44.362433+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-27T15:42:44.362485+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-27T15_42_44_356Z-debug.log
2022-09-27T15:42:44.488708+00:00 heroku[web.1]: Process exited with status 1
2022-09-27T15:42:44.596272+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-27T18:16:45.608999+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-27T18:16:49.175447+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-27T18:16:50.835566+00:00 app[web.1]: npm ERR! missing script: start
2022-09-27T18:16:50.841448+00:00 app[web.1]: 
2022-09-27T18:16:50.841597+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-27T18:16:50.841643+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-27T18_16_50_836Z-debug.log
2022-09-27T18:16:50.956922+00:00 heroku[web.1]: Process exited with status 1
2022-09-27T18:16:51.036539+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-27T20:17:09.845597+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-27T20:17:13.713641+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-27T20:17:15.434629+00:00 app[web.1]: npm ERR! missing script: start
2022-09-27T20:17:15.442596+00:00 app[web.1]: 
2022-09-27T20:17:15.442743+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-27T20:17:15.442766+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-27T20_17_15_435Z-debug.log
2022-09-27T20:17:15.720939+00:00 heroku[web.1]: Process exited with status 1
2022-09-27T20:17:15.772583+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-28T00:00:05.627095+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-28T00:00:09.137208+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-28T00:00:10.742614+00:00 app[web.1]: npm ERR! missing script: start
2022-09-28T00:00:10.747874+00:00 app[web.1]: 
2022-09-28T00:00:10.748017+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-28T00:00:10.748075+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-28T00_00_10_743Z-debug.log
2022-09-28T00:00:10.890627+00:00 heroku[web.1]: Process exited with status 1
2022-09-28T00:00:10.970157+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-28T05:34:46.738158+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-28T05:34:50.391709+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-28T05:34:51.849347+00:00 app[web.1]: npm ERR! missing script: start
2022-09-28T05:34:51.851744+00:00 app[web.1]: 
2022-09-28T05:34:51.851897+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-28T05:34:51.851941+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-28T05_34_51_849Z-debug.log
2022-09-28T05:34:51.974330+00:00 heroku[web.1]: Process exited with status 1
2022-09-28T05:34:52.033174+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-28T11:34:55.046139+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-28T11:34:58.574051+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-28T11:35:00.099011+00:00 app[web.1]: npm ERR! missing script: start
2022-09-28T11:35:00.104375+00:00 app[web.1]: 
2022-09-28T11:35:00.104525+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-28T11:35:00.104586+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-28T11_35_00_099Z-debug.log
2022-09-28T11:35:00.224223+00:00 heroku[web.1]: Process exited with status 1
2022-09-28T11:35:00.355310+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-28T17:03:07.139847+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-28T17:03:10.562012+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-28T17:03:12.213926+00:00 app[web.1]: npm ERR! missing script: start
2022-09-28T17:03:12.219849+00:00 app[web.1]: 
2022-09-28T17:03:12.220073+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-28T17:03:12.220148+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-28T17_03_12_214Z-debug.log
2022-09-28T17:03:12.344262+00:00 heroku[web.1]: Process exited with status 1
2022-09-28T17:03:12.403952+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-28T22:50:37.930709+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-28T22:50:41.621115+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-28T22:50:43.630788+00:00 app[web.1]: npm ERR! missing script: start
2022-09-28T22:50:43.636305+00:00 app[web.1]: 
2022-09-28T22:50:43.636533+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-28T22:50:43.636619+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-28T22_50_43_631Z-debug.log
2022-09-28T22:50:43.781331+00:00 heroku[web.1]: Process exited with status 1
2022-09-28T22:50:43.833316+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-29T04:42:47.113088+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-29T04:42:50.397810+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-29T04:42:52.194754+00:00 app[web.1]: npm ERR! missing script: start
2022-09-29T04:42:52.197188+00:00 app[web.1]: 
2022-09-29T04:42:52.197339+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-29T04:42:52.197401+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-29T04_42_52_195Z-debug.log
2022-09-29T04:42:52.335100+00:00 heroku[web.1]: Process exited with status 1
2022-09-29T04:42:52.443456+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-29T09:21:46.000000+00:00 app[api]: Build started by user koichan1996@icloud.com
2022-09-29T09:22:39.663542+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-29T09:22:49.727248+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-29T09:22:52.196442+00:00 app[web.1]: npm ERR! missing script: start
2022-09-29T09:22:52.201802+00:00 app[web.1]: 
2022-09-29T09:22:52.202011+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-29T09:22:52.202088+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-29T09_22_52_197Z-debug.log
2022-09-29T09:22:52.322556+00:00 heroku[web.1]: Process exited with status 1
2022-09-29T09:22:52.825835+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-29T09:22:52.834359+00:00 heroku[web.1]: State changed from crashed to starting
2022-09-29T09:23:01.182633+00:00 heroku[web.1]: Starting process with command `npm start`
2022-09-29T09:23:03.857801+00:00 app[web.1]: npm ERR! missing script: start
2022-09-29T09:23:03.862605+00:00 app[web.1]: 
2022-09-29T09:23:03.862739+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2022-09-29T09:23:03.862803+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-09-29T09_23_03_858Z-debug.log
2022-09-29T09:23:04.009321+00:00 heroku[web.1]: Process exited with status 1
2022-09-29T09:23:04.099238+00:00 heroku[web.1]: State changed from starting to crashed
2022-09-29T09:23:05.049527+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=fathomless-shore-68344.herokuapp.com request_id=000ea899-df59-4cd9-bf75-5ed0fdd5113a fwd="138.199.22.226" dyno= connect= service= status=503 bytes= protocol=https
2022-09-29T09:23:05.899592+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=fathomless-shore-68344.herokuapp.com request_id=f3189283-3490-4efd-b6bb-1b2f8e217cd5 fwd="138.199.22.226" dyno= connect= service= status=503 bytes= protocol=https
2022-09-29T09:22:39.338415+00:00 app[api]: Deploy a47a9f2f by user koichan1996@icloud.com
2022-09-29T09:22:39.338415+00:00 app[api]: Release v9 created by user koichan1996@icloud.com
2022-09-29T09:22:43.000000+00:00 app[api]: Build succeeded