For ProtonVPN as an example: you can go to the downloads section and download the wireguard config you want and then import it from the wireguard gui.
For me, I would never use other inferior VPN clients after knowing how efficient, supported and developed are the official Wireguard gui are.
Other providers who provide configs:



You stick the config in /etc/wireguard and then it’s just
wg-quick down endpoint1 ; wg-quick up endpoint2to switch locations. (Being wary that the VPN will be down for a moment.) You can name them whatever you like of course.Setting up DNS properly is not that hard and only needs doing once.