PHP Fatal error: Call to undefined function curl_init()

This error message indicates that the PHP script is trying to use the cURL library, which is not installed or enabled on the server. The function curl_init() is part of the cURL library, and is used to initialize a new cURL session. To fix this error, you will need to install and enable the cURL library on your server. The exact steps to do this will depend on your server's operating system and configuration. You can check the documentation of your server or contact your hosting provider for more information on how to install cURL on your server.