Ioncube on a plesk server

Hi, I have vps with plesk on it, i am going to install ioncube on it because i have a website hosted (As a ''customer''.)that needs it for whmcs on the back to work. But because of it being hosted it has restricted rights to my server, it has it's own space and can't interact with the the main vps directories. Because of this, it can't see some files of the ioncube installed on my server.