If you are using Mullvad, just go to their web page and look at the top bar to see if you are connected to their VPN or not.

In theory, as the article mentions, you should be able to save them to your password manager of choice (if it supports passkeys, bitwarden does on the browser extension but not in the android app yet) and they will sync up through the cloud. So you might have just one passkey for GitHub for example and use that same one on all your devices to log into GitHub.