Server Message Help

How can I make a script that works that after a user buys a developer product with the ID of 1884306040 the game will send a message every player can see saying which user bought the product?

You can use the ProcessReceipt callback to detect when a player buys a developer product, and after that loop through all the players and send send each of them a message.

Can you make a script that does that or smth?

As said above you can use the ProcesseReceipt system to detect when a sale is made on a product and use a RemoteEvent to send that Info to the server and to display a message to all clients ingame.

It’s actually pretty straight forward, here:

local MarketplaceService = game:GetService("MarketplaceService")
local Players = game:GetService("Players")

MarketplaceService.ProcessReceipt = function(receiptInfo)
  local player = Players:GetPlayerByUserId(receiptInfo.PlayerId)

  if not player then 
    return Enum.ProductPurchaseDecision.NotProcessedYet 
  end

  -- loop thru players and notify them

  return Enum.ProductPurchaseDecision.PurchaseGranted
end

This needs to be in a server (regular) script

I don’t think you get what I mean. I have a developer product that kills all players when bought and I want the game to send a message in the chat that everyone can see.

What I’m looking for the message to be “ has just bought the kill all product”

This is exactly what you need, when a player buys a developer product the ProcessReceipt callback is called.

You can do the notifying/applying effects by yourself.

Edit: I just realized what you mean, check out TextChatService, also this post