We are running Zulip Server 9.2, and we have users using a mix of desktop and mobile apps (both Android and iOS).
Currently, clicking on a video /audio call link in the Zulip mobile app causes the link to be opened first in a browser, which then presents the option to open the link in the Jitsi mobile app. There is a way to open the URL directly in the Jitsi app bypassing the browser on the mobile device, however this only works with the official Jitsi URLs. There does not appear to be a way to currently do this with self hosted Jitsi installations.
Would it be possible to modify the URL generated within the Zulip chat in the context of mobile apps, to generate the link such that the link is opened directly in the Jitsi app?
Feature request for Jitsi video call integration when implemented, originally submitted in https://github.com/zulip/zulip/issues/32178:
Relevant CZO discussion