Drone does not trigger any builds from Gitea

I set up Drone to work with Gitea. I can see all the repositories on the Drone main page, but whatever I do, no builds are triggered. I tried pushing new commits, creating new repos with .drone.yml, creating and merging pull requests, but still, no builds have been run.
There are no new logs in Drone server container after it started, though the web app appears to work fine. The latest one is: {"interval":"30m0s","level":"info","msg":"starting the cron scheduler","time":"2019-09-22T19:18:26Z"}
There are also no logs in the Drone worker container.
I noticed that there is no webhook in Gitea. Maybe Drone failed to create webhook somehow? Though I tried reinstalling it a couple of times.
Can someone please point me to what I am doing wrong?

see the following thread: Nothing happens when I push code, no builds, or builds stuck in pending

Thanks! The issue was with verifying self-signed certificate on the Gitea side.