FoxCall per The Dusk

FoxCall improves compatibility for encrypted voice and video calls on Facebook and Messenger when using Firefox.

It provides compatibility fixes for WebRTC and end-to-end encrypted calling features that may otherwise fail or behave incorrectly in Firefox.

Features include:

Improved Facebook and Messenger voice/video calling compatibility
WebRTC encoded-stream compatibility for Firefox
Compatibility handling for encrypted calls
Support for direct calls and multi-device call scenarios
No account required
No telemetry or user tracking

FoxCall operates locally in the browser and is not affiliated with, endorsed by, or sponsored by Meta, Facebook, Messenger, Mozilla, or Firefox.