i want to install the T4U on my raspberry pi 400, as the build in wifi is rather bad. tp-link does provide instructions for linux, which includes raspberry pi 3. as mine is a pi 400 so different chip i also got some info from Jeff Geerling. I managed to compile a kernal, reboot and start just fine. kernal version is from today so it looks like that worked. next step is to complie the driver source, and this is where i get lost. the Tplink instructions say 'go to the drivers directory, open the make file and do some commands'. The instructions dont mentiont to download the driver from the tplink website, but i did that anyway. unzipped it and edited the MakeFIle  as per instructions, albeit i changed BCM2709 to BCM2711 (pi 400 chip). i do make clean, and make, and ...

make ARCH= CROSS_COMPILE= -C  M=/home/pi/Archer T4U_V3_181018_Linux_beta/T4Uv3_WiFi_linux_v5.3.1_beta  modules
make[1]: *** M=/home/pi/Archer: No such file or directory.  Stop.
make: *** [Makefile:1998: modules] Error 2

so, i got stuck there. if anyone would be able to put me on the right path, that would be much appreciated.

ps i guessed the hardware version, and no clue about the firmware. i bought it last week on amazon from the tplink shop.

Regards