Per California, "Unlike the IRS, FTB does not offer an electronic signature option for our Business e-file Program. The business taxpayer, ERO, and paid preparer must sign the California e-file Return Authorization form (FTB 8453-C, FTB 8453-P , FTB 8453-LLC or FTB 8453-EO) prior to the transmission of the e-file return. This form may be retained by the preparer or business taxpayer according to the rules of our program or scanned and included as an attachment to the business e-file return. Do not mail this form to FTB."
For more information, please click this link: https://www.ftb.ca.gov/professionals/busefile/profaq.shtml
