If you are unable to make a purchase at the Monster Hunter Now Web Store, the following may be the cause

• Your payment method has been rejected.
• There is a problem with your login.
• The login method is not supported.
• The use of the payment system provided by the Monster Hunter Now Web Store is prohibited.
• A chargeback has occurred.
• There is a purchase for which a refund is pending.
• You are trying to purchase from a country or region that is not served by the Monster Hunter Now Web Store.

If you are unable to purchase from the Web Store, please try purchasing from the in-app store.Please refer to this support page for contact information regarding each issue.

Payment issues

https://niantic.helpshift.com/hc/faq/4229-my-payment-method-was-declined-ja-only/

Login issues

https://niantic.helpshift.com/hc/faq/3777-help-with-sign-in-issues/