Hi @_Jennifer_! There isn't a way to change the item type in the Square app, as item types aren't used in Square Point of Sale.
Item types are only used with Square Online, and their purpose is to alter the checkout behavior for customers. For the most part they're used to determine whether an item is available for shipping, though there are a few other things they do to change the checkout experience. For example, a customer purchasing a service item won't be asked for shipping information.
Is there something in particular that you're looking to do with your items? There may be other features in the Square app that could work for you instead of the item types.
