Oh hey, you're still embarrassing yourself by your inability to google.
https://postalpro.usps.com/mailing/competitivepoboxes
Move to Competitive Street Addressing for PO Boxes
In Move to Competitive Locations with Street Addressing, a customer's mailing address may be either the street address for the Post Office where their PO Box is located, followed by # and the box number, or PO Box followed by the box number.
Some merchants do not allow shipping to a PO Box address. The Street Addressing option enables customers to receive packages and deliveries from private carriers who require a street address for delivery, such as UPS and FedEx.
Note: Customers who sign the Customer Agreement should not submit a Change of Address (COA) from their PO Box to the associated street-style address because both addresses will be delivered to their PO Box.