The U.S. Postal Service regulates how postal mail can be received and handled in the United States. The USPS also dictates required procedures for commercial mail-receiving agents (CMRA) like your operator to follow.
The USPS Form 1583 is to authorize a CMRA to receive mail on the mailbox renter's behalf. It also ensures that a responsible party is linked to the mailbox. If you want to download it for your records, follow these steps.
Accessing and downloading your CMRA form
Go to your User Profile icon in the top right corner.
On the dropdown, click the ⚙️ Settings tab.
Go to the CMRA section at the bottom left.
Click the ⇩ download icon.
The file will open in a new tab.
Click the ⇩ download icon to download to your desktop.