Euro-Office and Office EU (office.eu) are not the same project.

How does Euro-Office compare to IONOS Workspace, office.eu, the Proton productivity suite, Nextcloud Hub or XWiki: Euro-Office is more of an integration component. It merely handles document editing itself. Storage, as well as navigation, permissions and sharing logic has to be offered by a platform it is integrated in, like Proton Docs, Nextcloud Hub or OpenProject. – https://github.com/Euro-Office/.github/blob/main/profile/README.md#faq