How to track the 12/stable snap?

I have the regular 11 snap installed and would like to track 12/stable or 12/edge. No amount of searching online or looking at the documentation tells me how to accomplish this. Setting up a snap is easypeasy, but this… I’m just stumped. Any help would be appreciated, thanks in advance!

NVM, I figured it out myself "snap refresh nextcloud --channel=12/edge"
But I have to say the interface, web etc. don’t make this obvious.

Hmmm… now, for whatever reason, I am no longer able to contact the server. The install process shows no error. How to troubleshoot this? Snap makes the initial setup painless, but maintenance sucks.