No problem!
Thanks!
I have been messing around with this for the past few hours and I haven’t been able to find a way to connect to Nextcloud over IPv6. Granted, I don’t have much experience with IPv6, but I think the idea behind IPv6 is that you can bypass port forwarding entirely as long as you have configured your network to allow incoming IPv6 connections.
If there is a way to connect to Nextcloud externally using IPv6, I am not sure whether it would involve going through Nginx Proxy Manager first or just connecting directly to the Nextcloud server (which, presumably, would require getting a unique IPv6 address for your Nextcloud server, which was something I wasn’t able to figure out how to do).
As per this post, it would appear that IPv6 is not officially supported for TrueNAS SCALE apps quite yet.