Can’t access my modem

While trying to fix my mesh system at home, I was asked to turn off the router part of my modem/router. This seems to have solved the mesh issues, but not I am unable to access my router via the app or through the same way I turned it off originally. I figure this is because the router part is off, but now I don’t know how to access those setting again.

I tried plugging in with a Ethernet wire, and going to 192.168.1.1 but that doesn’t take me anywhere.