How to integrate facebook with my game?

i know there are similar questions on the site but none of them received any good answer .i want to make a game in which facebook friends can be invited to play if they have downloaded the game like in pubg .i know pubg is built from unreal engine so there would be a way.please help.

This plugin is honestly your best bet, its not cheap though. Either that or you need to learn Facebook API and do it through code.