This page provides direct linking to US state vanity plate registration websites. You may find details and procedures for registration on appropriate state motor vehicle department website.
A vanity plate is a personalized license plate number in United States. They are issued by every U.S. state and District of Columbia. All states have a "Blue List" that contains a list of banned letter/number combinations, words or phrases. So be prepared it may be rejected if it is in the list.
Alaska Vanity License Plates
Alabama Vanity License Plates