how can i get players to recevie their inf backpack?

i wanted to know how can i make players get their inf backpack i have the purchase things done and they can buy it but wont recevie it

Got this from someone and this one increases speed but i need to know how can i make this one to give player infinite backpack

local id = 7001215

game:GetService("MarketplaceService").PromptGamePassPurchaseFinished:Connect(function(plr,ido,purchased)
	if purchased and ido == id then
		plr.Character.Humanoid.WalkSpeed = 30
	end
end)
 
game.Players.PlayerAdded:Connect(function(plr)
	plr.CharacterAdded:connect(function(char)
		if game:GetService("MarketplaceService"):UserOwnsGamePassAsync(game.Players[char.Name].UserId, id) then
			char.Humanoid.WalkSpeed = 30
		end
	end)
end)