GNU/Linux Ubuntu 20.04 ALFA Network AWUS036ACU Wifi Adapter Driver Setup – Step-by-step Guide
Hi! The linked Tutorial shows you Step-by-Step How to Install Alfa Network AWUS036ACU Wireless AC1200 USB Adapter Driver for Ubuntu 20.04 Focal LTS GNU/Linux.
And the Ubuntu Focal ALFA Network AWUS036ACU Setup is based on the Realtek rtl8811AU Chipset Driver Installation.
But the Realtek rtl8812AU/rtl8821AU Driver following the Realtek Documentation is supporting also the rtl8811AU Chipset.
So you may try first with the rtl8821AU Driver Setup and eventually switch to the rtl8812AU.
In case to check your Adapter Chipset see: How to Check Wireless Device ID on GNU/Linux.
GNU/Linux Ubuntu 20.04 Installing Alfa Network AWUS036ACU Wireless Driver