Yes anywhere you would normally use a Disney Gift card you can use the Spira. You can't add it in the App as a payment card, the number has to be inputted manually each time. When I went to pay for Lightning Lanes,
Genie+ and mobile ordering the option came up to use the stored credit card or pay with a Disney Gift Card. If you choose pay with gift card, you then get a space to type in the number on the Spira, the same as you would would with a normal gift card. At restaurants and shops they scan the barcode on the Spira, the same as they do normal gift cards.