How to minimize screen view in native android application?

Dear Team,

I have implemented Jitsi video calling in my android native application in java and it is working fine.
Now I just want my Jitsi screen in small size, as of now Jitsi video screen is opening in full screen then we can minimize (picture-in-picture mode) which is fine but in my case, I want my screen in small size(minimize size) when Jitsi screen will open then I can maximize (Fullscreen).

How to minimize my Jitsi UI screen when it is opening in native android application?

Thanks and Regards
Suraj Kumar