This is a script to install protonvpn and it's dependencies (some of which are not even mentioned in the arch wiki documentation).
The following pakages also need to be installed along with proton vpn :
networkmanager-openvpn network-manager-applet stalonetray
All this has been included in the script.
Just clone the script, make it executable with chmod +x proton-vpn-arch-install.sh , then run it with ./proton-vpn-arch-install.sh.