Connect 2 servers in 2 locations through a VPN

Hello
I have 2 nextcloud servers each running in a different location.
The users in Location A connect to the Nextcloud server in the their local Intranet.
The users in Location B connect to the Nextcloud server in the their local Intranet.

Both these servers are connected through a VPN connection.

I want to have users in Location A talk to users Location B using voice chatting or video calling.
Is this possible?

Can someone please Help