local skyID = "0" -- put ur texture (decal) id
local sky = Instance.new("Sky")

sky.SkyboxUp = "rbxassetid://" .. skyID
sky.SkyboxDn = "rbxassetid://" .. skyID
sky.SkyboxLf = "rbxassetid://" .. skyID
sky.SkyboxRt = "rbxassetid://" .. skyID
sky.SkyboxFt = "rbxassetid://" .. skyID
sky.SkyboxBk = "rbxassetid://" .. skyID

sky.Parent = game.Lighting