Thanks @Tony Yeah, I was playing around with the settings, and doing some research, and had changed the operation mode to Access Point after I wrote the original post. Although, I still had the cable...

I just got the TP-Link AX1800 (the manual says AX1800 / AX20, the router's firmware tab says AX21, so....), and I want to use it as basically an Access Point, but I also want to be able to get to the...