"script that opens a product prompt when the player clicks the ui button called DanceButton. if the player buys the product, every player in the server dances for 10 seconds. add comments to show what everything does and means."

-- script for the DanceButton
local DanceButton = script.Parent

-- function that is called when the button is clicked
function onClicked()
	-- open the product prompt for the product with the id 12345
	game:GetService("MarketplaceService"):PromptProductPurchase(game.Players.LocalPlayer, 12345)
end

-- connect the onClicked function to the MouseButton1Click event of the button
DanceButton.MouseButton1Click:Connect(onClicked)

-- server script

-- function that is called when a player buys the product
game.MarketplaceService.PromptProductPurchaseFinished:Connect(function(player, productId, isPurchased)
	-- check if the productId is the one we want and if it was purchased
	if productId == 12345 and isPurchased then
		-- loop through all players
		for _, player in pairs(game.Players:GetPlayers()) do
			-- make the player dance
			player.Character.Humanoid:LoadAnimation(script.Dance):Play()
		end
		-- wait 10 seconds
		wait(10)
		-- loop through all players
		for _, player in pairs(game.Players:GetPlayers()) do
			-- stop the player from dancing
			player.Character.Humanoid:LoadAnimation(script.Idle):Play()
		end
	end
end)