Am unable to add the payment method. Pop out says that to contact apple support

Pending purchases indicate a purchase that was unable to be charged successfully to your valid payment method on file or Apple Account balance, as such you are responsible for that purchase, and must allow it to successfully complete before anything else can be done.

If you can't make purchases or update apps, including free apps, you may need to have a valid payment method on file, even if the app you want to download is free.

See -> Add a payment method to your Apple ID

Add a payment method to your Apple ID – Apple Support (UK)

• If you want to change your card, add first the new card, then remove the old one.
• or if you want use your Apple ID balance, you need to set your Apple ID balance as your default payment.

See also the following Apple articles:⤵️

Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

FYI: Not all credit & debit cards seem to work with App Store / iTunes Store, try a different one, or preferably a credit card. If your card is not accepted as a paymenf method, you need to contact your bank.

Add money to your Apple Account balance -> Add money to your Apple Account balance - Apple Support

If you have set your Apple Account balance as your default payment method, your default payment method will be used first by Apple when you need to make a payment.

Some purchases might require you to have a credit card on file, even if you use your Apple Account balance to make the purchase.

Remove a payment method from your Apple ID

Remove a payment method from your Apple ID - Apple Support 

⤵️

If you can't remove a payment method

If you have subscriptions like iCloud+, have an unpaid balance, or you use purchase sharing, you must keep at least one payment method on file.

• Do you have a subscription? You can cancel iCloud+ and cancel other subscriptions from Apple. When your subscription period is over, remove your payment method.
• If you're in a Family Sharing group and you use purchase sharing, the family organizer must have a payment method on file. If you're the family organizer, turn off purchase sharing, then remove the payment method.
• If you have an unpaid balance, you might not be able to remove a payment method. Instead, change your payment method.
• If you still can't remove a payment method, contact Apple Support.

If you still need help, get support from Apple directly -> Get Support or call Apple in your region see -> Contact Apple for support and service or check -> here for more support and assistance.