How To Limit Characters In TextBox[Solved]

[Ma7adi805 (III)]

Hello, I am Making A Discord Application But On Roblox and I need to take users discord id and discord id is 18 characters so I would like to limit the user to only enter 18 characters, I made a script about it but there it is not working somehow

local submitbutton = script.Parent.Submit
local ws = require(script.Parent.WebhookService)

local url = "can't give"
local Players = game:GetService("Players")
local Hellotext = script.Parent.UserName
--local optionaltextval = script.Parent.PlayerSaying
local userid =game:GetService("ReplicatedStorage"):WaitForChild("DiscordId")
local PlayerSaid = game:GetService("ReplicatedStorage"):WaitForChild("PlayerSaying")
local TweenService = game:GetService("TweenService")
local textboxclosed = UDim2.new(1.5, 0,0.331, 0)
local discordidclosed = UDim2.new(1.5, 0,0.808, 0)
local submitshowppsitoin = UDim2.new(0.063, 0,0.422, 0)
local DiscordButtonTween = TweenService:Create(script.Parent.DiscordID, TweenInfo.new(1), {Position=discordidclosed})
local textboxTween = TweenService:Create(script.Parent.TextBox, TweenInfo.new(1), {Position=textboxclosed})
local submitshow = TweenService:Create(script.Parent.SubmittedText, TweenInfo.new(1), {Position = submitshowppsitoin}) 

local peoplewhoapplied = {}
local Min = 10^17.99
local Max = 10^18

local stirnglen = string.len(userid.Value)

submitbutton.MouseButton1Click:Connect(function(player)
	for _, p in pairs(Players:GetPlayers()) do
		local useridint = tonumber(userid.Value)
		if (tonumber(userid.Value))then
			
			if table.find(peoplewhoapplied, useridint) then
				p:Kick("Apparently The Id You Entered Is Already Verified, Screenshot This If Your Not Verified")
			elseif not table.find(peoplewhoapplied, userid.Value)  then			
				--if string.len(userid.Value) >=10^18  then
				if stirnglen==18 then
					print(useridint)
					
					if userid.Value=="" then
						submitbutton.Text="Error"
						wait(1.5)
						submitbutton.Text="Submit"
					elseif userid.Value~="" then
						submitbutton.Text="Submitted"
						local playername = p.Name
						local playeruserid = p.UserId
						textboxTween:Play()
						DiscordButtonTween:Play()
						submitshow:Play()
						submitbutton.Visible=false
						local fields = {
							{
								['name'] = playername.." said nothing",
								['value'] = "Submitted By: "..playername.." | "..playeruserid,
								['inline'] = true
							}
						}
						local digit = math.clamp(useridint,1000000000000000000,999999999999999999)
						print(userid)
						ws:createEmbed(url, "New Application", "Submitted By <@"..userid.Value..">", fields)
						wait(3.5)
						--p:Kick("Application Submitted Succesfully")
					end
						
				elseif stirnglen~=18 then
					submitbutton.Text="Digit Number Should Be 18 digits"
					print(useridint)
					wait(2.5)
					submitbutton.Text="Submit"
				end
				
			end	
		else	
			submitbutton.Text="Error"
			wait(1.5)
			submitbutton.Text="Submit"
		end
		
end
	
	
		
	
	
end)




	

[calvin_coco (where)]

local max = 18

TextBox:GetProperyChangedSignal("ContentText"):Connect(function()
    TextBox.Text = TextBox.ContentText:sub(1,max)
end)

[Ma7adi805 (III)]

The Script Worked, but could I ask what is the difference between ContentText And Text

[Dev4q]

Content text is the text that gets replicated to the server