[Solved] Wireguard dns leak on the mobile device

No, you do not. Any DNS server you choose can be used. As I already stated in another thread you created:

For example, if your Wireguard server is an OpenWRT router, simply use the router's Wireguard endpoint IP as the DNS server. You may have to change the assigned IP from a /32 to the actual size of the subnet, so the appropriate route will be made on the mobile device.

Hope this helps.