Hi there,
I have run the first script that is on this page
I can log into the wireguard server that it created but I did not have external access, i.e. access to the web.
I changed this line
uci set firewall.${LAN}.network="${firewall_zone} wg_${firewall_zone}"
to
uci set firewall.${LAN}.network="${firewall_zone} wg_${firewall_zone} wan"
and that solved my issue.