Any person described in Section 3302 who desires to register and vote under this chapter shall apply in writing to the elections official of the county in which the person was last domiciled prior to departure from the United States. When an overseas voter as described in Section 3302 applies for a vote by mail ballot, the application shall be deemed an affidavit of registration and an application for permanent vote by mail status, pursuant to Chapter 3 (commencing with Section 3200).