Hi
Follow the instructions here:
If you don’t see your in-app purchases - Apple Support
If you added or updated a payment card for the App Store, keep in mind that an authorisation request may also have been made to your card issuer. This is not an actual charge, just a check to ensure that your payment card is active and able to be used when paying for your transactions.
When a temporary authorisation hold is placed on your credit card or payment method, it will only be for a low, nominal amount (for example, in the US, you might see a $1.00 USD charge). Any such charge will be removed automatically from your card account and will not need to be paid.
About payment card authorization holds in the iTunes Store - Apple Support
If you still need help, contact iTunes Support:
Contact - Official Apple Support