American Express cardholders in the U.S. can enter their americanexpress.com user ID and password, rather than their primary account number, to settle payments online at Burberry, Warby Parker, Intermix, Newegg, Wall Street Journal, Ticketmaster, BarkBox, Ledbury, and Sabon. Amex Express Checkout will soon also be available at Avis, Banana Republic, Cole Haan, Gap, Old Navy, 1-800-Flowers, and some of the merchants using Stripe to process their transactions. Merchants receive code and application programming interfaces (API) to execute Amex Express Checkout on their shopping carts. They do ...