There is no way to upgrade from CentOS 7 to CentOS 8.
We tried the options posted online, and none worked.
What we did, is we brought up a new CentOS 8 server and then used the CWP Migration tool to move over the accounts/sites.
Then about 2 weeks after this, CentOS announced that CentOS 8 would end, and be replaced with CentOS Stream.
If you are on CentOS 7, I would recommend you stay on that OS and wait and see what happens with Rocky Linux, etc and CWP.