ErrorException: curl_exec() has been disabled for security reasons in /var/www/vhosts/phumcareermatching.com/httpdocs/www/vendor/mpdf/mpdf/src/Mpdf.php:11927
first check if the curl is working properly. Open your php.ini file and check for disable_functions over there. And see whether your curl_init is packed there or not!
curl_exec was disabled on your hosting, exactly as the error message says.
The used disable_functions directive can be changed only in the global php.ini file, which will most likely not be possible on a shared hosting.
You could ask the hosting support to allow it, but I guess they have their reasons to disable it, so they will be reluctant to do so.