u/Downtown-Mixture-254

I'm English but have dual nationality as my dad is Irish and already have an Irish passport in my dead name. I was looking to update my Irish passport with my new name and gender through the statement of declaration and proof method, but when I was looking through the online application I couldn't see how to actually change my gender marker for my new passport and just wanted some help. Thanks!

I have changed my name via an unenerolled deed poll and updated my name with my university and bank, however not my passport or gotten a GRC yet as the process is so long. I was wondering if I can register to vote with my new name or if they won't accept it as it won't match my current passport?