USB wifi adapter

I have a Rock4C+ which I want to create a wifi hotspot to work as a WiFi extender. We (my son) managed to get it to create a wifi hotspot, but unfortunately it then also disconnect from our router.
I don’t want to pull a network cable half way through the house, and therefore bought a WiFi usb adapter, which can also create a hotspot and work on Linux ( I figure that would include Debian). We have found drivers for the usb adapter, it is a Realtek 8811 chip, install, rebooted etc. we have tried following different guides, hence also different drivers, but for some reason we cannot even see the usb adapter listed in the possible wifi connections.
Is there any go to please, guide or anything that just works?