You may be worried about holding up the line with a cart full of items, trying to figure out how to purchase a digital gift card. Understandable! First it's important to remember that delivery of digital gift cards is nearly instantaneous. Many users find it takes less time than waiting for your chip enabled debit or credit card to go through. Certainly takes less time than a check. Beyond that you have some options
1. Have the app pulled up and ready to go with the merchant already displayed and ready to type in the amount you need. Get the total from the cashier, type in that amount, checkout, and the gift card will display. You simply show that to the cashier who scans enabled gift cards or enters the gift card number.
2. Estimate! Gift card balances don't expire, so you can purchase a large value gift card at places you shop often, and pull the same gift card up every time you visit until depleted. If your estimate is low, you can still use a second payment method (like your debit or credit card, or even a store branded charge card to get points!).
With either of these methods, you will earn cash back on the value of the gift card purchased.