Why can a bot go offline?

Question

Heroku

The bot was uploaded to heroku 3 months ago and has been working fine these days. Today, for reasons unknown to me, it turned off. Can you please tell me why this could happen?

Answer 1

Heroku gives you 550 (or so) free hours of app "activity" for free (regardless of type). Probably because of this.
The limit can be increased by linking the card (in my case, a virtual machine from qiwi came up (named account, with a zero balance))

Answer 2

Maybe some technical work on the main server or someone may have manually disabled the project.

Make sure this slider is set to On</i>