Go to the Profile menu at the top right of the rezora app and select My Account.
At the top of the right column, you'll find the email address area. The Account email address is used for signing into the Admin account. Admin accounts with a connected agent profile also have a choice, to send emails from the "Account email" or from a different address.
Remember that your "Account email" address is the username that you will use to log in!
After making any changes, click the Save Changes button at the top.