NordVPN client needs login, and under Linux want to use browser for authentication. The use of browser can be tedious, so we can use a simple parameter to despite browser.

nordvpn login --legacy​

And stay in peace with the lonely terminal. In some other cases, users have also used another parameter, after login in the browser

nordvpn login --callback "nordvpn://success-uri-from-browser"

but I find it more verbose