A. 1. Use an alternative payment method: If you have another credit or debit card, consider using that for your order. 2. Check for other payment options: Look for options like PayPal or Apple Pay within the app, which may be accepted. 3. Contact your bank: If you believe your Amex should be accepted, contact your bank to ensure there are no issues with your card. 4. Provide feedback: Use the app's feedback feature to express your desire for Amex acceptance in future updates.