USB wifi dongle that I could easily add to my router?

Hi all,

I've got the below router set up in my garage with a wifi client on the 2.4ghz connected to my home, and an access point on the 5ghz. Problem is I need a 2.4 access point there as well. Sounds like I might just be able to add a cheap dongle to the usb port on the router and set it up as an AP though, that right?

If so, could someone recommend a dongle I could just connect, reboot, and then find in wireless settings?

Thanks!

Model: Linksys Viper (E4200v2 / EA4500)
Architecture: Feroceon 88FR131 rev 1 (v5l)
Firmware Version: OpenWrt 19.07.1 r10911-c155900f66 / LuCI openwrt-19.07 branch git-20.029.45734-adbbd5c
Kernel Version: 4.14.167