Currently, we don't support adding any AMEX accounts. We made a business decision years ago to stop doing business with American Express, so that's why you can't add AMEX accounts to EveryDollar. We don’t have plans to add AMEX to EveryDollar at this time.
*If you're seeing American Express show up in the list of institutions, that shouldn't be happening. It may tell you to check back in a few hours, but that error is wrong. There is not a way to add AMEX to EveryDollar.