Feature Request: Selfhosting collaboration server

[AinzRimuru]

Feature Request

If possible, I hope to have a platform that supports local collaboration and does not rely on any Internet services. I'm using draw.io on nextcloud and I want to be able to implement collaborative editing of diagrams. Using onlyoffice on nextcloud gave me a very good experience of collaboratively editing documents, so I was wondering if there was anything I could learn from that.