An exchange can add as many admin accounts or broker accounts by converting a member account to either broker or admin.
An account can only have one status: member, broker or admin.
If you want to make a broker account an admin account, then remove the broker status to make it a member account again, and then make the member account an admin account.
One admin account must be a default admin, or nothing will work, as the system won’t know where to deposit trade fees.
To initiate an Amazon SES validation email, which is required to send system emails from VB, simply login as the default admin, then send an email to a member, which should trigger an SES validation email sent to your email address.