Mother passed away and I'm getting conflicting answers about next steps for her estate. Texas.

Location: Texas.

My mother passed away last week. I still have yet to receive the death certificates, but I've gathered all of her financials and provided first notices to the institutions. My mother had a living trust that she placed her home and created two bank accounts for. Her bank has two accounts for the trust and 3 accounts that were personal. All of those accounts were listed in a bill of transfer and notice of assignment to become property of the trust that appears to have been executed. I am listed in the trust to become the trustee upon her passing.

I've been told I need to get a letter of testamentary, and go before a probate judge to be recognized as the executor of her will/estate in order to touch those accounts. I've also been told the opposite.

Can anyone provide me with clarity about what I should expect to need to pursue given the information above?