Turns out the Omada er605 v2 doesn't support this vpn protocol. I guess I will have to wait for their Wireguard Protocol. I contacted the Adguard VPN support and they said that there are very few...

I recently got these credentials (as shown in pic) from Adguard VPN to configure the router for VPN access. I browsed through the settings of router and couldn't find anywhere to put those...