Image failure to load in after using a variable to change images?

So i'm trying to make an in-game power-point system where the user clicks a part, and enters the ID of a decal and the decal will show up on the image label/ surface GUI.

heres the script so far

script.Parent.FocusLost:Connect( --in a text box so the player can enter the decal ID
	function(enterPressed)
		if enterPressed then
			script.Parent.Value.Value = script.Parent.Text
			script.Parent.Parent.Visible = false
			script.Parent.Text = "Text Here..." --ignore everything above this
			local part = game.Workspace.ShowPart
			local value = script.Parent.Value.Value
			part.SurfaceGui.ImageLabel.Image = ("http://www.roblox.com/asset/?id="..value)
		end
	end
)`

error message:

"Image "https://assetdelivery.roblox.com/v1/asset?id(image i want)" failed to load in "Workspace.ShowPart.SurfaceGui.ImageLabel.Image": Request failed

I tried using the rbxasset:// thingy, everything else system wise is working. sorry for sloppy, first post new to this website

i am not looking for criticism with my code, I've been scripting for a few months and im pretty proud of how far i've come

I'm not sure if this will work but I did my best! Here you go. This should function as you intend it to.

local Workspace = game:GetService("Workspace")
local TextBox = (script.Parent:IsA("TextBox") and script.Parent) or script:FindFirstAncestorOfClass("TextBox")
TextBox.PlaceholderText = ("Text here!");
TextBox.FocusLost:Connect(function(EnterPressedEvent)
	if not EnterPressedEvent then
		return
	end
	local ShowPart = Workspace:FindFirstChild("ShowPart")
	local Value = TextBox.Value.Value
	pcall(function()
		local SurfaceGui = ShowPart:FindFirstChildOfClass("SurfaceGui")
		SurfaceGui:FindFirstChildOfClass("ImageLabel").Image = ("rbxassetid://") .. string.match(TextBox.Text,("%d+")); -- "%d+" is a pattern type which gets the digits in the string.
	end)
end)