I want to add a payment modded

See >>> Change, add, or remove Apple ID payment methods - Apple Support

If you only have a single Credit Card set-up for your AppleID account, you will need to add a new Credit Card to your AppleID account - after which you will be able to delete the old card details. 

It is often a good idea to have two (or more) payment cards associated with your account - as, in case there is a problem with your primary card, a charge can be made to the second card without risk of impacting ongoing access to your AppleID account or associated services and subscriptions. With multiple Credit Cards, you can choose the sequence in which card payments are made.

You may find these support pages to be helpful:

If you need to change or update your Apple ID payment method - Apple Support

Add a payment method to your Apple ID - Apple Support

Remove a payment method from your Apple ID - Apple Support

Payment methods that you can use with your Apple ID - Apple Support

Assuming that your payment card is supported, if you cannot resolve the problem yourself, you would be best advised to seek assistance directly from Apple Support:

Official Apple Support

You can also initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/app/apple-support/id1130498044

Marryputting177 wrote:

I want to add a new payment method

This document explains how to add a payment method to your Apple ID on a Mac, Apple mobile devices, PC, or online --> Add a payment method to your Apple ID - Apple Support

If you then want to remove and old payment method, read this article --> Remove a payment method from your Apple ID - Apple Support

Ongoing subscriptions and Family Sharing organizers must always have a payment method present. To edit the cards used for those you may need to first add the new card and make it the primary payment method before removing the old card (see: If you need to change or update your Apple ID payment method - Apple Support ).

Yes a want to add payment