Can I install mPDF in cPanel?
Yes, mPDF can be installed and will work with MultiPHP Manager. mPDF is a number of PHP classes in '.php' files rather than a compiled binary module which must be loaded into the core PHP service/daemon.
The official method for installing mPDF is through composer using the following:
composer require mpdf/mpdf
Please note that the amount of assistance with installing, configuring or troubleshooting this module is limited.