roblox GetProductInfo.Sales returning nil?

Hello, I am working on a script which is meant to check the sales on a Developer Product. Here is my script:

local PRODUCT_ID = 433463734
 
local MarketplaceService = game:GetService("MarketplaceService")
 
local productInfo = MarketplaceService:GetProductInfo(PRODUCT_ID, Enum.InfoType.Product)
 
print(productInfo.IconImageAssetId)
print(productInfo.Sales)

I was trying to use '.Sales' because it seems to be displayed as Sales on this website: https://api.roblox.com/docs But for some reason It returns nil? The IconImageAssetId works fine though? How can I fix this.

From what I saw from the docs, .Sales doesn't work with developer products

https://gyazo.com/c14641e3fde7353c61d69cfd195c56ea

(Sales is listed under Assets)