Twitch-cli EventSub test passes but API responds webhook callback verification failed

Yes. It’s a valid SSL cert generated with LetsEncrypt/certbot.

I’m not sure I understand the question. Are the received requests being written to a log file? Yes. It’s running on nginx which logs everything, but my script does not.

The nginx logs don’t affect the HTTP response, however, so I don’t think I understand what you’re asking.

Yes. It’s running on a VPS with ports 80 and 443 accessible to the world.