SQLi 2ndOrder Lab - PHP Error

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Hi there, I’m trying to solve the SQLi 2ndOrder Lab. In my .php-script I’m using “curl_init”. However, when the function is being called, my Apache webserver returns a 500 Internal Server Error. In the error.log I’m getting a “call to undefined function curl_init()”.
According to some resources online, I need to install php-curl, but on the machine we don’t have internet access. So how can I fix this?

Any help appreciated, thanks!