How can I make a friend invite core GUI pop-out?

I saw that the game "Pet Ranch Simulator" has this feature where you can invite friends in-game. I want to make something similar, but i don't know how the function or service is called.

local plr = game.Players.LocalPlayer
local gui = script.Parent
local service = game:GetService("InviteService?")

gui.MouseButton1Click:connect(function()
	service:PopOutFunctionHere(plr.UserId?, invites)
	if invites > 0 then
--things here
	end
end)