By the way, in the App Store of Nextcloud 34 itself, in the Office & Text category, they’ve integrated a new section right at the top that lets you easily switch between the two:
However, it seems that this is only for the connector apps and that you still need to install the respective document server separately: either the Collabora Docker container, the Built-in CODE Server (richdocumentscode), or, in the case of Euro-Office, the Docker container that I linked to above (at least for now).