You may need to add an RPM so it is available to cPanel users but isn't within cagefs.
The command to use here is
cagefsctl --addrpm <rpm name>
for example, to add the ftp client to be available this would be run
cagefsctl --addrpm ftp
Then the following needs to be run
If further information is needed on cagefsctl options please refer to: cagesctl CLI Options