What are the SIP providers that works with Jitsi Desktop?

Hi Jitsi team and community !
We would like to use SIP with the Jitsi Desktop application for PC & Mac, but could you please tell us what are the best SIP providers that works with Jitsi Desktop ?
We tried to use OnSIP, but seems like it is not working… Also some others, and same.

What the SIP providers you can advice, that works good for video-conferences with Jitsi Desktop (free or not).

Thanks for your support!

Regards

Any sip provider which is doing NAT traversal (latching) for media should work. For example we were extensively using ippi and there should still be an ippi protocol provider in the app.