Our own private, self-hosted Forgejo instance that we use often enough that using it as an identity provider is not a big hassle :)

If you have no cookies or expired ones, oauth2-proxy will take you a page with a simple "Log in with OpenID Connect" button, which then takes you to the login page of the Forgejo instance. If you're not logged in, then you provide your credentials. Otherwise, you get redirected back to Jitsi with cookies that are good for a week.

I didn't remember, so I had to Google: Forgejo is the recent Gitea fork that itself is a Gogs fork. To save some people some clicks.

https://news.ycombinator.com/item?id=34011581

Forgeto

You can run your own, there are a lot of open source IDPs.