This video guide below was done last year on Kali 2019.2. Because we found the process to be identical for Kali 2020.1, we decided against recording a whole new video. Watch the video below to see how to install Alfa AWUS036ACH or AWUS1900 on Kali Linux 2019.2 or 2020.1 with monitor mode & injection support.
This also works for AWUS036AC.