Yep couple options. Through umbrel you’ve got your login (and I would always use 2fa) to limit access. 

Within btcpay specifically you can set user profiles with different permissions. For example an employee login having different capabilities than the business owner. 

With tailscase the ip address for a specific app on umbrel has the port number included. You could save the app page as a bookmark, connect tailscale, open bookmark and login with any btcpay user profile.