Thank you both for your helpful information gentlemen. However, I may have found what I was looking for: "umbrel@umbrel:~/umbrel/tor/data/app-albyhub$ sudo nano hostname" via SSH in UmbrelOS contains a .onion address to my local Alby Hub instance that successfully loads in a Tor browser. Please let me know if I am conflating the issue and the onion address I found isn't what Fedimint is asking for.

LDK tor support is still in the works -> https://github.com/lightningdevkit/ldk-node/issues/178

Public and Tor addresses for the node need better visibility and configurability. It's okay to hide things and set defaults for new users, but there should be an "advanced mode" available where these settings are exposed and users can configure them as needed.