You may submit Form N-565, Application for Replacement Naturalization/Citizenship Document, online or by mail.
If you choose to use a paper version of Form N-565, you should mail it to the following address:
USCIS Phoenix Lockbox
For U.S. Postal Service (USPS):
P.O. Box 20050
Phoenix, AZ 85036
For FedEx, UPS, and DHL deliveries:
1820 E. Skyharbor Circle S
Phoenix, AZ 85034
In order to be on the safe side about where to send/mail Form N-565, you may also check the current valid mailing address on USCIS official website or call National Customer Service Center.
Please note that when you submit Form N-565 through the mail, you receive a USCIS Account Acceptance Notice in the mail with instructions on how to create a USCIS online account. However, you are not obliged to use your online account, USCIS will continue to send you copies of notifications regarding your case by mail.
And if you would like to receive a text message and/or an e-mail that your Form N-565 has been accepted at a USCIS Lockbox facility, you must complete Form G-1145, E-Notification of Application/Petition Acceptance, and clip it to your Form N-565.