Can you add on to the GL-AR750S Wiregaurd and an add blocker?
Do you mean Ad blocker?
How does it relate to wireguard?
Wireguard and an add blocker like addgaurd or pinhole?
It should be AdGuard, not Addguard.
For AR750s there is a firmware with Adguard http://download.gl-inet.com/firmware/snapshots/3.105_beta2/ar750s-agh/
Pls note, AR750s is not powerful enough to run Adguard smoothly.