ios - Best way to select quantity of items for an eCommerce mobile application?

I'm designing an e-commerce app, and I'm looking for some options for the best way to select the quantity of an item before adding to the cart

The first (on the left) is when the user selects the Quantity, and the iOS drop-down selection is be triggered and the user can update that way.

Or on the right, the user can increment by pressing + or -