Region3 only execute command once if player enters region

Hi, is it possible to only execute a command once when a player enters a Region3?
I am thinking that ‘debounce’ wont work as it will only switch from true and on.

local part = script.Parent
local region = - part.Size/2, part.Position + part.Size/2)

while true do
	local partsInRegion = workspace:FindPartsInRegion3(region, nil, 1000)
	for i, part in pairs(partsInRegion) do
		if part.Parent:FindFirstChild("Humanoid") ~= nil then

The purpose is to execute a remoteevent which activates a gui for the player.

Just check if the player’s PlayerGui folder already contains the gui which is being given, if it does don’t give them it.