Can I file for my deceased father, even if my brother is the personal representative?

My brother and I are the only children of my father who passed away in July 2024.  He did not have a will nor was he married, so we designated my brother as the personal representative of my dad's estate.

I am ready to complete my dad's taxes for 2024.

- Should I log into his previous TurboTax account to complete?

- Am I able to electronically sign, even though my brother is the official personal representative?