Wireguard Basic error in Script

In https://openwrt.org/docs/guide-user/services/vpn/wireguard/basic under 2

WG_PUB="$(cat wgclient.pub)"

prints an error because the file wgclient.pub isnt created before.
Can someone fix this please?

So, you need to save the client public key as wgclient.pub on the server.