herokuにデプロイする際にエラーが発生しました。

###エラー内容
gyazo
https://gyazo.com/7eda7790f8d235ea95e908710ea4824f
Application errorというエラーが発生しました。

% git push heroku master

を実行しても

Everything up-to-date

が返ってきます。

画像の通りheroku logsでエラー文を確かめました。

##ターミナル

2020-10-08T01:43:57.788772+00:00 app[web.1]: npm ERR! missing script: start
2020-10-08T01:43:57.796326+00:00 app[web.1]: 
2020-10-08T01:43:57.796622+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2020-10-08T01:43:57.796728+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2020-10-08T01_43_57_789Z-debug.log
2020-10-08T01:43:57.852296+00:00 heroku[web.1]: Process exited with status 1
2020-10-08T01:43:57.910108+00:00 heroku[web.1]: State changed from starting to crashed
2020-10-08T01:43:57.915270+00:00 heroku[web.1]: State changed from crashed to starting
2020-10-08T01:44:00.000000+00:00 app[api]: Build succeeded
2020-10-08T01:44:00.596960+00:00 heroku[web.1]: Starting process with command `npm start`
2020-10-08T01:44:03.502920+00:00 app[web.1]: npm ERR! missing script: start
2020-10-08T01:44:03.510195+00:00 app[web.1]: 
2020-10-08T01:44:03.510583+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2020-10-08T01:44:03.510740+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2020-10-08T01_44_03_503Z-debug.log
2020-10-08T01:44:03.586011+00:00 heroku[web.1]: Process exited with status 1
2020-10-08T01:44:03.628536+00:00 heroku[web.1]: State changed from starting to crashed
2020-10-08T01:47:02.064515+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=4cd63fab-1215-4123-9748-6c98078d8bba fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:47:02.553264+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=6d1e2ea9-2a6b-4ffd-9a4d-0d3b5b6f379c fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:47:58.446159+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=0ac0a00e-5896-4fe9-b7ac-2af533d92493 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:47:58.820594+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=f6ce6fa0-5829-409f-a17d-98f5e383a8d8 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:24.735263+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=52199c69-e2f3-4538-9088-0952cd98d5ac fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:25.109044+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=8f7404aa-2836-4cbc-bb51-c5e49ddedaa3 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:26.045625+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=524d6c71-a26e-4d92-b201-451ef840acfb fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:26.423549+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=8d0025c2-57c5-4b8c-aa55-0dabb462ab00 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:27.345062+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=7616b494-7a3f-4fc9-88f3-98ed085d7420 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:48:27.697064+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=fc01b8eb-68fc-45f1-ba52-0c9a09ea8626 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:53:11.946513+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=8c07341f-1fcd-438e-ac29-0f5b0de418fe fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:53:12.299195+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=d762c599-eefb-4f8d-9006-f55a9c0e04ae fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:53:25.777769+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=task0202.herokuapp.com request_id=2db3467d-cbaf-4fb0-96b4-6f3465735581 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https
2020-10-08T01:53:26.111076+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=task0202.herokuapp.com request_id=684af77c-69b8-402b-8daf-32cbcd6b3919 fwd="122.102.251.69" dyno= connect= service= status=503 bytes= protocol=https

###試したこと

2020-10-08T01:43:55.910202+00:00 heroku[web.1]: Starting process with command `npm start`
2020-10-08T01:43:57.788772+00:00 app[web.1]: npm ERR! missing script: start
2020-10-08T01:43:57.796326+00:00 app[web.1]: 
2020-10-08T01:43:57.796622+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2020-10-08T01:43:57.796728+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2020-10-08T01_43_57_789Z-debug.log
2020-10-08T01:43:57.852296+00:00 heroku[web.1]: Process exited with status 1
2020-10-08T01:43:57.910108+00:00 heroku[web.1]: State changed from starting to crashed
2020-10-08T01:43:57.915270+00:00 heroku[web.1]: State changed from crashed to starting
2020-10-08T01:44:00.000000+00:00 app[api]: Build succeeded
2020-10-08T01:44:00.596960+00:00 heroku[web.1]: Starting process with command `npm start`
2020-10-08T01:44:03.502920+00:00 app[web.1]: npm ERR! missing script: start
2020-10-08T01:44:03.510195+00:00 app[web.1]: 
2020-10-08T01:44:03.510583+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2020-10-08T01:44:03.510740+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2020-10-08T01_44_03_503Z-debug.log
2020-10-08T01:44:03.586011+00:00 heroku[web.1]: Process exited with status 1
2020-10-08T01:44:03.628536+00:00 heroku[web.1]: State changed from starting to crashed

ここになにかヒントがあるのかとおもい、エラー文を調べてみましたがなにが原因なのかがわかりません。
ご教授お願い致します。