Collabora with Apache2 - Unauthorized WOPI host error

I managed to setup Collabora with Apache2 on DigitalOcean, but now when I enter my URL in my NC install on diffrent server I get this error:

Unauthorized WOPI host. Please try again later and report to your administrator if the issue persists.

Why, how can I use for example on for example my NC install on

Do I need to add, etc. to my Collabora server setup

Any help would be great