dynoの再起動に伴うものですた。すみませーん
2020-12-11T18:55:33.394208+00:00 heroku router - - at=error code=H20 desc="App boot timeout" method=POST path="/inbox"
2020-12-11T18:56:03.558379+00:00 heroku router - - at=error code=H12 desc="Request timeout" method=GET
2020-12-11T18:56:03.620082+00:00 heroku router - - at=error code=H12 desc="Request timeout" method=GET
2020-12-11T18:56:14.768315+00:00 heroku router - - at=error code=H12 desc="Request timeout" method=GET