The easiest way I found was to format a pendrive (FAT32) on the PC, name it CONFIG, create a folder called network, create a my-network file with the contents:
[connection]
id=my-network
uuid=72111c67-4a5d-4d5c-925e-f8ee26efb3c3
type=802-11-wireless
[802-11-wireless]
mode=infrastructure
ssid=Your SSID
#Uncomment below if your SSID is not broadcasted
#hidden=true
[802-11-wireless-security]
auth-alg=open
key-mgmt=wpa-psk
psk=Your Password
[ipv4]
method=auto
[ipv6]
addr-gen-mode=stable-privacy
method=auto
this done he should connect to his wireless network. You can remove the pen drive then, you don’t need to put it on anymore.