HerokuにデプロイしたRailsAPIを訪れると404が返ってくる。

前提

herokuのログを見ても特にエラーは起きていません。
自分の状況と近いと思われるredditの投稿を見たところ、おそらくroutingの問題だと思うのですが、ローカルでは問題なく動いていたので解決方法がわかりません。

herokuのlog

2021-03-17T14:05:11.996185+00:00 heroku[web.1]: Restarting
2021-03-17T14:05:11.998661+00:00 heroku[web.1]: State changed from up to starting
2021-03-17T14:05:14.036185+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2021-03-17T14:05:14.121622+00:00 app[web.1]: - Gracefully stopping, waiting for requests to finish
2021-03-17T14:05:14.136068+00:00 app[web.1]: Exiting
2021-03-17T14:05:14.236153+00:00 heroku[web.1]: Process exited with status 143
2021-03-17T14:05:35.434690+00:00 heroku[web.1]: Starting process with command `rails server -b 0.0.0.0`
2021-03-17T14:05:43.675856+00:00 app[web.1]: => Booting Puma
2021-03-17T14:05:43.675872+00:00 app[web.1]: => Rails 6.1.2.1 application starting in production
2021-03-17T14:05:43.675872+00:00 app[web.1]: => Run `bin/rails server --help` for more startup options
2021-03-17T14:05:46.461396+00:00 app[web.1]: Puma starting in single mode...
2021-03-17T14:05:46.461833+00:00 app[web.1]: * Puma version: 5.2.1 (ruby 2.6.6-p146) ("Fettisdagsbulle")
2021-03-17T14:05:46.461879+00:00 app[web.1]: *  Min threads: 5
2021-03-17T14:05:46.461915+00:00 app[web.1]: *  Max threads: 5
2021-03-17T14:05:46.461953+00:00 app[web.1]: *  Environment: production
2021-03-17T14:05:46.461995+00:00 app[web.1]: *          PID: 3
2021-03-17T14:05:46.462328+00:00 app[web.1]: * Listening on http://0.0.0.0:23271
2021-03-17T14:05:46.527269+00:00 heroku[web.1]: State changed from starting to up
2021-03-17T14:05:46.614866+00:00 app[web.1]: Use Ctrl-C to stop
2021-03-17T14:05:52.350910+00:00 heroku[router]: at=info method=GET path="/" host=foodlist-back.herokuapp.com request_id=b0feac3e-55aa-4143-adad-4f927d976518 fwd="121.85.241.175" dyno=web.1 connect=0ms service=11ms status=404 bytes=255 protocol=https