The following error can happen on your system when your cPanel and WHM server is having difficulty creating outbound connections:
Requesting script ... httpupdate.cpanel.net did not have any working
mirrors. Please check your internet connection or dns server
at /usr/local/cpanel/Cpanel/HttpRequest.pm line 921.
This problem can show up when working with Yum, cPanel automated updates that run overnight, or when trying to add features to the system through the EasyApache 4 interface. If the server isn't able to make outbound connections, it won't be able to contact the mirrors to download those updates.
The best thing to do in this situation is to make sure that all the necessary ports are open for traffic on the system. We have a guide at How to Configure Your Firewall for cPanel & WHM Services that explains what ports need to be open in order for a cPanel system to function, so checking your server settings against the details in that guide will help to resolve this issue.
If things are working well you should be able to run the following command:
telnet httpupdate.cpanel.net 80
and get a result similar to this:
# telnet httpupdate.cpanel.net 80
Connected to httpupdate.cpanel.net.
Escape character is '^]'.