Changing Email

I'm an educator and I created this account during Covid lockdown (virtual learning). I've kept the account even though we are back face to face. I created the account with my school email address. As of the end of this school year I've resigned from that school and district and have transferred to a new one. I want to change my email address associated with the account, but am unable to access I old school email. Because I have a Basic account I don't have access to a live representative (according to the Chatbot). How can I go about changing the email associated with this account?