If your credit card isn’t going through, try the following:
Make sure your billing address matches the address on file with your bank.
Enter your name and card number exactly as shown on the card.
Add the correct CVV (3-digit code on the back of the card; 4-digit on the front for Amex).
Ensure your card has sufficient funds or is not being blocked for fraud protection.
If the problem continues, please contact your bank or card issuer for assistance.