If you're having trouble making a payment on your Apple account, the first thing you should do is check to see if there are any outstanding payments that need to be made. If you have an unpaid balance, Apple will oftentimes put a hold on your account until the balance is paid in full. To check your outstanding balance, simply sign into your Apple account and click on the "Account" tab. From there, you should be able to see your current balance and payment history.
If there are no outstanding payments on your Apple account, then the next step is to check your payment method. Apple accepts various payment methods, but sometimes there can be issues with specific methods. For example, if you're trying to use a debit card to make a payment, Apple may require that you have a credit card on file as well. If you don't have a credit card on file, you can add one by going to the "Payment & Shipping" section of your Apple account and clicking on "Add Payment Method."
If you're still having trouble making a payment on your Apple account, the next step is to contact Apple support. Apple has a team of experts that can help you troubleshoot any payment issues you may be having. You can reach Apple support by phone, chat, or email. To find the best method of contact for your specific issue, Apple has a handy support page that you can use.
[Edited by Moderator]