I can't find a driver for this adapter model
TP-Link does not provide any official drivers for Linux-based operating systems. They do have a download page for the T4U, but the kernel support is limited to 2.6.18 to 4.11. Newer kernels are not at all supported.
That said, you may be able to get by with one of the open drivers. This will be 100% dependent on the chipset in your T4u, though.
If your network adapter is using the
RTL8812AU chipset, then this driver from thelinuxguy should work for you.
If you have a European model, which may use the
RTL8822A chipset, then you'll need to find something that works. Unfortunately I do not have any experience with that specific chipset, so do not know where you can find a driver.