Adding a Second Root User to CPanel WHM

I needed to add a second root account to gain access to adding sites and making admin changes

SSH to the server and run the following commands:

useradd secondrootuser
passwd secondrootuser
usermod -aG wheel secondrootuser
echo "secondrootuser:all" >> /var/cpanel/resellers

Once that is done login to WHM at root and search for Resellers

Then click on Edit reseller Nameserver and Privileges

Check the boxes that you want the new second root user to have then apply and test logging in with the new user

Reference:

[cPanel/WHM] Creating second WHM user with root privileges (time4vps.com)