Plex tv Autopay want it automatically add a User after user pay When a user buys Service off my website i want it to automatically add User to plex -- 4

Plex tv Autopay want it automatically add a User after user pay When a user buys Service off my website i want it to automatically add User to plex -- 4 Hello i read your project completely and would like to offer you my service can u please message me so we can discuss. I am Good at Graphic Design, Website Design, HTML, PHP and JavaScript. Please Send me a message so that we can discuss more about this project