Roblox moving platform script

-- Moving platform: slides from its start position to START + OFFSET and back.

local OFFSET = Vector3.new(0, 0, 40)   -- how far to move (x, y, z in studs)
local TRAVEL_TIME = 4                  -- seconds for one trip
local WAIT_AT_ENDS = 1                 -- seconds to pause at each end

local TweenService = game:GetService("TweenService")

local platform = script.Parent
platform.Anchored = true

local startPosition = platform.Position
local endPosition = startPosition + OFFSET

local info = TweenInfo.new(TRAVEL_TIME, Enum.EasingStyle.Sine, Enum.EasingDirection.InOut)
local forward = TweenService:Create(platform, info, { Position = endPosition })
local backward = TweenService:Create(platform, info, { Position = startPosition })

while true do
	forward:Play()
	forward.Completed:Wait()
	task.wait(WAIT_AT_ENDS)

	backward:Play()
	backward.Completed:Wait()
	task.wait(WAIT_AT_ENDS)
end