Custom XMPP server

Hi!
I have setup self hosting using docker. I see these lines in .env files. I want to ask if I can use my own server for this? and how?

XMPP domain for the MUC

XMPP_MUC_DOMAIN=muc.meet.jits

yeah I also use the Openfire server as an XMPP server but i used it 2 years ago. but I recommend go with the prosody because they have implemented other modules as well.

thanks.