If all payment methods on your iTunes account are invalid, there may be the following situations:

Incorrect payment information: Please confirm whether the payment information you filled in is correct. If the payment information is incorrect, the bank or payment platform may prevent funds from being debited from your account.

Problems with the bank/payment platform: Sometimes the bank or payment platform's system fails, preventing transactions from being completed.

Expired or declined credit card: If you are paying with a credit card, the transaction may not be completed because the credit card has expired or been declined.

Payment is restricted: Sometimes, banks or payment platforms will impose restrictions on certain payments, such as cross-border payments, large payments, etc.

To resolve this issue, here are a few things you can try:

Check that your payment information is correct and make sure there are no errors.

Confirm whether your bank card or payment platform account is normal, and eliminate the impact of its failure.

Try to change other bank cards or payment platforms for payment.

If none of the above methods can solve the problem, it is recommended to contact iTunes customer service for help, and they will help you check and solve the problem.