How to make a disappearing door with OnClick func and variables (roblox lua)?

Assuming you already have the ClickDetector object inside of the door:

Hello!

So basically, you need to use this:

 -- IN A SERVER SCRIPT, INSIDE OF THE DOOR --
local door = script.Parent  -- door variable
local cD = script.Parent.ClickDetector  -- click detector
local event = game.ReplicatedStorage.Clicked -- This will be used to make the door LOCAL, so that people cannot get through with their friends.

cD.MouseClick:Connect(function(player)  -- gets the player after a click
    event:FireClient(player, door)  -- fires onto client
end)

 -- IN A LOCALSCRIPT, IN STARTERPLAYERSCRIPTS --

local event = game.ReplicatedStorage:WaitForChild("Clicked")  -- gets the event

event.OnClientEvent:Connect(function(door)  -- when the event is fired
    door.CanCollide = false -- canCollide false
    door.Transparency = 0.5 -- transparency 0.5
    wait(1) -- change to whatever you'd like
    door.Transparency = 0  -- transparency = 0
    door.CanCollide = true  -- canCollide true
end)

Hope this works!