Send group invitation after typing !group

First of all, I didn’t write in ‘What do you need help with? v3’ thread because I rarely get any answer there, even thought I provide every information I can.
But back to the topic, I want to send group invitations to players that type !group in chat.
I know how to do function that runs by typing !group in chat and all that stuff, the only thing I am having problem with is invitation sending, since as I think it’ll require usage of either mysql or php, does it not ?

Thanks in advance!