Happy to have you in Community again, steve63. I'd be glad to answer your post.
First off, for me able to provide you with the best resolution, could you please provide me with additional information about the P Card you're referring to?
If you're trying to set up payment information of your client, by default, the accepted cards in QuickBooks Payments are Visa, MasterCard, Discover, and Amex.
For reference, you may find this article helpful:
Add or modify the accepted credit card types (payment method) in QuickBooks.
For future help, you can read these great resources:
However, if you mean something else, please let me know. I'm looking forward to hearing from you.