Ubuntu 20.10 based distros do not support the rtl88x2ub Wifi USB adapter out of the box.

Internet connection via Bluetooth

There's a catch 22 when installing a rtl88x2ub WiFi adapter driver. First you need to download it from the Internet but your Linux is not ready to connect to a WiFi.

Instead of using another PC to download a driver and copy to a USB flash drive simply use Bluetooth tethering on your mobile:

• buy a Bluetooth dongle for your desktop PC
• enable Bluetooth tethering and turn on a hotspot on your mobile
• pair and connect to your mobile phone from your PC

Installing rtl88x2ub drivers

If you are looking for rtl88x2ub drivers for Linux you have probably already seen the github.com/cilynx/rtl88x2bu repo. Unfortunately its build process did not work for me on my Ubuntu 20.10-based system. The source files simply did not compile (both 5.3.1 and 5.8.1).

Error! Bad return status for module build on kernel
Consult /var/lib/dkms/rtl88x2bu/5.3.1/build/make.log for more information.

./rtl88x2bu-5.3.1/include/rtw_security.h:252:8: error: redefinition of ‘struct sha256_state’
  252 | struct sha256_state {

I have found another solution in the following repo instead: github.com/morrownr/88x2bu.

Below are instructions for Ubuntu taken from that repo's README:

sudo apt-get update
git clone https://github.com/morrownr/88x2bu.git
cd 88x2bu
sudo ./install-driver.sh
sudo reboot