This seems to sort-of working. However, if I have multiple domains, this solution attempts to redirect everything to the one domain I put in here.
How to I address this issue? Specifically, I want to use the nextcloud client to connect to the shared cloud storage for different domains. So if I have abc.com and xyz.com, I need to use https://abc.com/cloud to access files for that domain and https://xyz.com for files on the latter domain.
The mail works fine for multiple domains, as does the admin page, but cloud does not.