hello
I have been given three tplink devices :
TL-WR841N/ND V9
TL-WA901ND V4
TL-WR841N/ND V11.1
problem is, I dont see on the openwrt ar71xx packages, how to get the wireguard one
the idea is to connect device in AP+sta (i already did it years ago), then to get the router itself as a wireguard client, to connect to VPN for computers.
well, I thought about compiling it... (I have no other money for buying a new hw)
Hi.
These are 4/32 MB devices. They are outdated and very limited comparing to actual specs. To simply install 21.02 on them, you will have to go through very customized builds. I don't dare to talk about 22.03. So don't even think about installing wireguard on these. 
I have been given such a device lately, and I transformed it into a managed switch under 21.02. That's the best it can do.
For the background
these devices are explicitly unsupported these days and even with very dedicated intent, it's close to impossible to make them do anything sensible with current code. They really need replacing, as relying on EOLed releases with known security issues isn't an option either.
those are not enough outdated to make them retired :
thank you 