Tax returns for decedent and estate

Hi, I have to file a 1040 for my parent who passed away in 2023. I also need to file a 1041 for the income of the estate (there is a trust but the cash and stock assets were NOT transferred into it, so those items were distributed under a small estate affidavit -- but some interest/dividends were earned prior to distribution). I want to do DIY Premium or Live Assist for both. How do I set this up?

For the 1040:

- Do I set up a TurboTax account in the name of the decedent? Or should the TT account be in my name?

- How do I show the IRS that I have the authority to file? Do the trust and pour-over docs will have to be notarized again, do they have to be mailed in with the return?

- It appears 2021 and 2022 decedent 1040 returns were not filed by the decendent. Can I just file those under the same TurboTax account I set up for 2023?

For the 1041:

- TT shows that I must buy a business account and choose "For Estae or Trust." However, when I go to open the account, it asks me for a business name. There is no button or way to select "Trust or Estate". If I enter the name of my parent in the business name field, I get an error. Please make it clearer how to set up the account. Again, in my own anme or the decedents, and how to show it is for the estate?

- How do I show the IRS that I have the authority to file? Do the trust and pour-over docs will have to be notarized again, do they have to be mailed in with the return?

- If income is low enough that the 1041 is not required, will TurboTax show me that?

Thanks!