CentOS 8 support is here in version 92 of the cPanel software. However, cPanel version 92 is not currently the default version installed on new servers.
To install cPanel version 92, you must select a tier it is available in. You can check which tiers version 92 is available by visiting our Releases site.
At this time, version 92 is available in "Edge" and "Current," so one of those will need to be used when installing.
To select your release tier when installing, first create an /etc/cpupdate.conf
# nano /etc/cpupdate.conf
Then simply install as normal.