Adding a VIP on website fully automatic
 

Is there an API for Sourcemod that allows such thing to happen so in the end I'm left with forwards of "OnVIPBought(const char[] AuthId)" Or something similar? ( and obviously for security reasons I need to fire back to the forward that I did my job in the database so I never deal with refunds and fails )

Re: Adding a VIP on website fully automatic
 

I don't know if it helps, but I found some Panel that adds privileges on the server, see if any is what you are looking for.

https://github.com/Summer-16/CSGO-VMPanel
https://www.tebex.io/

You can try to find something for the VIP Core: https://github.com/R1KO/VIP-Core

There is one that is completely Russian: https://gamecms.ru/

See if any of these can help you. I particularly recommend Tebex, a problem that needs another plugin so that it can send commands to add privileges, I believe.