Ik how to find out if a player enters region3. But how do i find out if player has left region3?

		while true do
			wait(0.5)
			local partsinregion = workspace:FindPartsInRegion3(region, part, 1000)
			local playerFound = {}
			for i, part in pairs(partsinregion) do
				if part.Parent:FindFirstChild("Humanoid") ~= nil then
					print("Player found in region!" .. part.Parent.Name)
					playerFound[part.Parent.Name] = true
					
					
					local playerr1 = part.Parent.Name
					local playerr2 = game.Players:FindFirstChild(playerr1)
					local frame = playerr2.PlayerGui.Craftinggui.Frame
					frame.Craftingtablegui.Visible = true
					
					
				end
			end
		end
	end
end

You could try having a table and inserting the player's name into the table once the player has walked into the region3. and the while loop could also try running through the table containing all players who entered region3 and checking if the person is still in the region3 or if they person is not in the region3.