Hi @roland-wilden,
the repo with “documentseditor” in the url is the one only available to Kopano customers with a valid subscription. If you don’t have a subscription you have to follow the instructions at https://documentation.kopano.io/kopano_loo-documentseditor/installation.html#installing-libreoffice-online-community-repository.
However I have to add that both repositories only include the backend parts and no frontend integration into WebApp (for that solutions like nextcloud/owncloud still would need to be used). There was unfortunately never enough interest to develop this proof of concept any further.