Subject line is the question. Can one use the USB port on satellite router instead of main router for a thumb or external hard drive?

I set up a Netgear EAX80 mesh extender (it was a gift). It appears to have logged onto my network and I think is acting as a mesh device. But it's hard to tell. I can log directly onto it, and it does

Please work up a way for one to be able to log onto a satellite router directly. Also, please allow a way for the LEDs on satellite routers to be controlled differently from the main router.

I set up one Archer AX55 Pro (or AX3000 Pro, depending on what you look at) as a main and another as a satellite. Why is it not set up so that one can log onto the satellite? What is "Rejected request