Asterisk 20 is still in the testing repos, so attempting to install without having the sangoma-devel16 repo enabled will fail. There are still some issues that are being worked on, until then I recommend you stick to Asterisk 18.
Asterisk 20 is still in the testing repos, so attempting to install without having the sangoma-devel16 repo enabled will fail. There are still some issues that are being worked on, until then I recommend you stick to Asterisk 18.