Process for closing account after death

Context: My dad died last week. I don't believe he is currently under a contract...i have access to his online account. Equipment is from 2018 according to his account online. I have a death certificate and an online obituary. He lived in an apartment (rental). I live 100 miles away and am the executor of his estate.

What are the keywords or prompts I need to say/do to get me to someone who will reasonably work with me on this?

Thanks in advance.