Install ioncube on CentOS Plesk Server
To install ioncube on Plesk server, run
yum install plesk-php56-ioncube-loader plesk-php70-ioncube-loader plesk-php71-ioncube-loader plesk-php72-ioncube-loader
To verify ioncube installed, create a PHP file with following content
Upload it to server and access the file via web browser. You will see phpinfo. This will show ioncube if installed properly.