Intergrating Clickatell API's with my system

Hi guys, I am new both on Github and Clickatell.

I have developed a Php PDO sms system, it works well on my local server without any third-party scripts, and my issues is that i want to intergrate Clickatell scripts to enable my system to send SMS’s live. On the clickatell-php-master folder i see two sub-folders (src and test), I am not sure if that’s all I need to runtest my SMS system.

And what file do i have to include on my send_sms.php file?

Please help me, the I only have 4 days left for the campaign to end.

Thank you in advance.