These are the steps on how to change the admin email account by using the Terminal.
Info on the Terminal:

https://support.danian.co/portal/en/kb/articles/terminal-info

1. Hover over your app square + click the Gears icon

2. Up+Right, click on the Terminal icon

3. Copy paste this command:
sudo -E -u www-data php spark shield:user list

4. Copy paste this command:

sudo -E -u www-data php spark shield:user changeemail 1

5. Enter this:

6. Enter this:

7. It will ask you what is the email that you pick. Enter it. Example:
newemailaccount@domain.com

8. The system will confirm that the change has been applied.

9. Up+Right - click on the icon: Restart app