Janus - Request - provide user choice to configure their STUN/ TURN server

Freedombox Version:
Debian GNU/Linux trixie/sid and FreedomBox version 23.19

Explanation:
Janus is a WebRTC app included in the Freedombox ecocsystem. Currently Janus is configured to use Coturn as the STUN/TURN server. However, Freedombox has another STUN/TURN server: ejabberd.

The existing plinth configuration page for ejabberd provides user freedom to configure their STUN / TURN server of choice (checkbox with Automatically manage audio/video call setup).

Request:
An option similar to ejabberd for configuring STUN/TURN server is requested for Janus. Other than Coturn, the user can be given freedom to use the ejabberd STUN/TURN server or a server of their choice.