Verify that you are logged in with the account that made the purchase.
Your PNP account may be linked to a different email than your Apple, Google Play or PayPal account. If you originally signed in through Google or Apple ID, be sure to use the same login method to access the same account.
NOTE: If you are an Apple user and your pass does not appear in your account, I would comment that if you logged in with Apple Connect, they would have generated a hidden email for your account for privacy reasons. This account ends at @privaterelay.appleid.com.
Try logging into the PNP app using the Apple login option, to see if this allows you to log in with the subscription purchase.
If this doesn't work, and if you don't know which address was used, you may need to contact Apple to find out.
You can find information about this on Apple's support pages here: