https://wiki.almalinux.org/elevate/ELevate-quickstart-guide.html#upgrade-steps

sudo dnf install -y http://repo.almalinux.org/elevate/elevate-release-latest-el$(rpm --eval %rhel).noarch.rpm
sudo dnf install -y leapp-upgrade leapp-data-rocky
sudo leapp preupgrade
sudo sed -i "s/^AllowZoneDrifting=.*/AllowZoneDrifting=no/" /etc/firewalld/firewalld.conf
sudo leapp answer --section check_vdo.confirm=True
sudo rm -rf /usr/share/redhat-logos

We need to disable Root Login (was enabled up to EL8)

sudo vi /etc/ssh/sshd_config #PermitRootLogin
sudo leapp preupgrade

Study any other messages and try to resolve:

sudo less /var/log/leapp/leapp-report.txt
sudo leapp upgrade
sudo reboot; exit