How can I get my LB-Link Wi-Fi 6 USB adapter working on Kubuntu?

The simplest and most reliable option is usually to exchange it for a USB Wi-Fi adapter with a chipset supported by Linux's built-in kernel drivers. That avoids downloading source code, compiling modules, and troubleshooting the adapter after future updates. Panda Wireless adapters are one example, but check current Linux compatibility before buying.

If you only need temporary internet access, use Ethernet if possible. If the desktop has no Ethernet port, a USB Ethernet adapter can get you online long enough to install packages or investigate the Wi-Fi driver. A USB hub may be necessary if you are short on ports.

Search for the exact model together with “Linux driver” and verify that the instructions match the adapter's chipset. If you find a maintained driver, you can download its source and required packages using the laptop, transfer them by USB, and compile it on the Kubuntu desktop. Be aware that this is a more advanced and less dependable route.

This adapter may not have an official Linux driver. The manufacturer appears to provide Windows drivers only, so it may require compiling an unofficial third-party driver. That can work, but it may need to be rebuilt after kernel updates and could be difficult to maintain.