1

Can you add on to the GL-AR750S Wiregaurd and an add blocker?

2

Do you mean Ad blocker?

How does it relate to wireguard?

3

Wireguard and an add blocker like addgaurd or pinhole?

4

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.