If you have already purchased a JetBackup license, you can install it using the following instructions:
To install JetBackup on cPanel:
Run the installation commands:
yum clean all --enablerepo=jetapps*
yum install http://repo.jetlicense.com/centOS/jetapps-repo-latest.rpm
yum install jetapps-cpanel --enablerepo=jetapps
jetapps --install jetbackup stable
Further information can be found here:
https://docs.jetbackup.com/