hi @icarlberg welcome to collabora online forum
humhub.local:9980 is just the example URL from HumHub’s local Docker dev guide, so it cannot work for their SaaS instance. They need a publicly reachable Collabora server with HTTPS - either self-hosted with their license, or they ask HumHub if their SaaS hosting provides one. Plus the WOPI allow list on the Collabora side.
Thanks
Darshan