Hi. this worked for me
Install Repo :
dnf -y install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm
Disable default Repo :
dnf -qy module disable postgresql
Now you will have options installing any version from 9.5 to 13 so we want 13, installing from the CWP panel, so we need to disable all other versions except for 13
Edit pgdg-redhat-all.repo and disable by changing "1" in to "0" under other versions at line "enabled=1" :
nano /etc/yum.repos.d/pgdg-redhat-all.repo
Save and Exit / Quit (for nano - personal choice is Ctrl+o > Enter > Ctrl+x
Run Update :
dnf -y update
Now you should see only v13, Reboot, Login to panel, install from it, wait, trying to refresh a blank page will show, no post install summary or options, now Reboot again (just in case) and phpPgAdmin will show, but server will not start, enable it in panel in "Services Config" > "Startup Services", again > Reboot, but service wont start, or will try to start with an error, and stop. Execute as root :
chown -R postgres:postgres /usr/pgsql-13/bin/
.. and now :
sudo su - postgres
... finaly :
/usr/pgsql-13/bin/initdb -D /var/lib/pgsql/13/data/
Reboot - and voila ... v13 up and running ..