Nordvpn & wireguard

I am using Manjaro-kde and Nordvpn with wireguard. Nordvpn works fine except it shows me a limited connection about a minute. I tried to modify resolv.conf but after restarting the computer the problem is the same. How to fix this problem please?

By following the Archwiki tutorial I do not understand this error: $ nordvpn set protocol TCP Command 'protocol TCP' doesn't exist.