如何解决？可能是什么错误？

Procfile

web: gunicorn cinemax_project1.wsgi --log-file -

runtime.txt

python-3.6.0

heroku logs --tail

2020-06-15T20:39:10.153847+00:00 app[api]: Initial release by user reabko15@gmail.com
2020-06-15T20:39:10.153847+00:00 app[api]: Release v1 created by user reabko15@gmail.com
2020-06-15T20:39:10.277545+00:00 app[api]: Release v2 created by user reabko15@gmail.com
2020-06-15T20:39:10.277545+00:00 app[api]: Enable Logplex by user reabko15@gmail.com
2020-06-15T20:39:36.373684+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/robots.txt" host=cinemax-pro.herokuapp.com request_id=924ecfb7-79b6-4862-aedf-5a2cc5890be4 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T20:39:36.377134+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=02137a73-107f-4901-b088-9d603b177421 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T20:39:38.108114+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=e8927bdd-c0e1-4947-9ecc-558d6c147474 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:20:49.168164+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=f8fdcd5f-0b89-4536-b98d-b7df338c0ea1 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:20:50.129115+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=fd291277-dd68-4fd5-bf8c-032ad0556bf6 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:34:07.000000+00:00 app[api]: Build started by user reabko15@gmail.com
2020-06-15T21:34:27.730338+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=61ccf003-e221-4c0a-aa4b-37b907f51c89 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:34:29.581338+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=f0be4f95-6fcb-4885-a097-d5a8cb43c4be fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:34:36.669483+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=41935700-6acc-4e51-8dac-bf65e10fac10 fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:34:37.281816+00:00 heroku[router]: at=info code=H81 desc="Blank app" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=ac94c1ac-5650-417d-be9f-f6763422fabb fwd="176.120.63.253" dyno= connect= service= status=502 bytes= protocol=https
2020-06-15T21:34:53.000000+00:00 app[api]: Build failed -- check your build output: https://dashboard.heroku.com/apps/92cd5a10-b6ca-4d7d-a279-7e36c5b09856/activity/builds/a173a1ad-9d4c-4456-95dc-cf1292b6abc7
2020-06-15T21:46:04.000000+00:00 app[api]: Build started by user reabko15@gmail.com
2020-06-15T21:47:12.506445+00:00 app[api]: Running release v3 commands by user reabko15@gmail.com
2020-06-15T21:47:12.506445+00:00 app[api]: Attach DATABASE (@ref:postgresql-concentric-59920) by user reabko15@gmail.com
2020-06-15T21:47:12.520386+00:00 app[api]: @ref:postgresql-concentric-59920 completed provisioning,setting DATABASE_URL. by user reabko15@gmail.com
2020-06-15T21:47:12.520386+00:00 app[api]: Release v4 created by user reabko15@gmail.com
2020-06-15T21:47:13.210243+00:00 app[api]: Deploy a223c855 by user reabko15@gmail.com
2020-06-15T21:47:13.210243+00:00 app[api]: Release v5 created by user reabko15@gmail.com
2020-06-15T21:47:13.230808+00:00 app[api]: Scaled to web@1:Free by user reabko15@gmail.com
2020-06-15T21:47:20.390231+00:00 heroku[web.1]: Starting process with command `gunicorn cinemax_project1.wsgi --log-file -`
2020-06-15T21:47:22.092587+00:00 app[web.1]: bash: gunicorn: command not found
2020-06-15T21:47:22.147780+00:00 heroku[web.1]: Process exited with status 127
2020-06-15T21:47:22.320922+00:00 heroku[web.1]: State changed from starting to crashed
2020-06-15T21:47:22.323009+00:00 heroku[web.1]: State changed from crashed to starting
2020-06-15T21:47:28.000000+00:00 app[api]: Build succeeded
2020-06-15T21:47:29.392563+00:00 heroku[web.1]: Starting process with command `gunicorn cinemax_project1.wsgi --log-file -`
2020-06-15T21:47:31.317608+00:00 app[web.1]: bash: gunicorn: command not found
2020-06-15T21:47:31.365585+00:00 heroku[web.1]: Process exited with status 127
2020-06-15T21:47:31.414130+00:00 heroku[web.1]: State changed from starting to crashed
2020-06-15T21:47:41.113682+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=8b905d45-f34e-43f8-99fd-18e07f1f32ed fwd="176.120.63.253" dyno= connect= service= status=503 bytes= protocol=https
2020-06-15T21:47:42.636120+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=162d77a5-223d-4efd-908f-4395a823e17a fwd="176.120.63.253" dyno= connect= service= status=503 bytes= protocol=https
2020-06-15T21:51:07.000000+00:00 app[api]: Build started by user reabko15@gmail.com
2020-06-15T21:52:01.565019+00:00 app[api]: Deploy a223c855 by user reabko15@gmail.com
2020-06-15T21:52:01.565019+00:00 app[api]: Release v6 created by user reabko15@gmail.com
2020-06-15T21:52:02.754339+00:00 heroku[web.1]: State changed from crashed to starting
2020-06-15T21:52:10.767607+00:00 heroku[web.1]: Starting process with command `gunicorn cinemax_project1.wsgi --log-file -`
2020-06-15T21:52:12.950053+00:00 app[web.1]: bash: gunicorn: command not found
2020-06-15T21:52:12.995263+00:00 heroku[web.1]: Process exited with status 127
2020-06-15T21:52:13.024938+00:00 heroku[web.1]: State changed from starting to crashed
2020-06-15T21:52:16.000000+00:00 app[api]: Build succeeded
2020-06-15T21:53:27.820694+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=cinemax-pro.herokuapp.com request_id=277e138e-f5f1-4ae8-9856-b86a877c2308 fwd="176.120.63.253" dyno= connect= service= status=503 bytes= protocol=https
2020-06-15T21:53:29.519112+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=cinemax-pro.herokuapp.com request_id=dbfaaeb9-2f22-457d-9285-9880f9cf302c fwd="176.120.63.253" dyno= connect= service= status=503 bytes= protocol=https
2020-06-15T21:59:12.113542+00:00 heroku[web.1]: State changed from crashed to starting
2020-06-15T21:59:19.870165+00:00 heroku[web.1]: Starting process with command `gunicorn cinemax_project1.wsgi --log-file -`
2020-06-15T21:59:22.547203+00:00 heroku[web.1]: Process exited with status 127
2020-06-15T21:59:22.592032+00:00 heroku[web.1]: State changed from starting to crashed
2020-06-15T21:59:22.462376+00:00 app[web.1]: bash: gunicorn: command not found