403 forbidden with http requests/http service?

local Players = game:GetService("Players")
local HttpService = game:GetService("HttpService")
local msg = script.Parent.Parent.ApplicationFrame.ApplicationArea.Text
local plr = script.Parent.Parent.Parent.Parent.Parent
local webhook = "https://discordapp.com/api/webhooks/443187425033060411/FLQ9s-L5qRzC7D20v4jaZ3epzXm7ngcJb0H7_QyOmTVNZkqkPFwKt7CQX0IbPORMJO6q"

script.Parent.MouseButton1Click:Connect(function()
        plr.sab.Value = true
        local data = {
            content = "```" .. script.Parent.Parent.ApplicationFrame.ApplicationArea.Text .. "```";
            username = script.Parent.Parent.Parent.Parent.Parent.Name;
            avatar_url = "http://www.roblox.com/Thumbs/Avatar.ashx?x=100&y=100&Format=Png&userId="..script.Parent.Parent.Parent.Parent.Parent.UserId
        }
    HttpService:PostAsync(webhook, HttpService:JSONEncode(data))
    plr:Kick("Your application has been submitted!")
end)

I'm using a discord webhook not sure if that effects it but it works in studio and not in game.