Collabora Online itegration with Nextcloud 22.2.5 Enterprise, Managed by IONOS

I am trying to integrate Collabora with Nextcloud managed by IONOS
Collabora will be on a seperate server
My issue is that when I follow some of the you tube videos and documentation I run into various problems relating to reverse proxy
I am looking for someone to help me out.
Cannot afford to pay for paid support
Any help appreciated