Not less than seven days before any runoff election, any voter entitled to vote by vote by mail ballot as provided in Section 10530 of the Elections Code may file with the county elections official, either in person or by mail, his or her written application for a vote by mail ballot. Vote by mail voting shall be conducted in accordance with the provisions of Section 10530 of the Elections Code.
Source:
Section 22970.20, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=WAT§ionNum=22970.20..