How to script a gui that changes a decal by putting a decal id

This is my error, what I want to achieve is in the title lol. I’ve tried researching and nothing has come up while researching.

Here is my block of code.
local textbox = script.Parent
local decal = game.Workspace.Part.Texture

decal.Texture = textbox

It is currently inside of the UI in a local script.

decal.Texture = textbox.Text

Whenever I try changing it after loading into a game, it does not change. Here is the script.

local textbox = script.Parent
local decal = game.Workspace.Part.Texture

decal.Texture = textbox.Text

Im not understanding what you mean?