Heroku error code=H10

Hello everyone, I’m stuck at deplying my backend with heroku and mangodb. I tried to resolve this issue myself reading about people who had the same problem as me but it didn’t work. I have set vidly_db to this link

After that, I follow mosh step but when I ran it, it didn’t work
and I’ve got that error

2021-07-22T10:41:40.354575+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=lit-gorge-35731.herokuapp.com request_id=2fbe798c-3a72-4075-8d8b-e27a4e035975 fwd="" dyno= connect= service= status=503 bytes= protocol=https