Currently SecureAPlus access right is tied to Windows account. There is no extra password needed, other than Windows password.
If you would like to dedicate a certain Windows user id to be able to modify the settings, you and add the Windows user id that you trust to modify settings in the trusted user list. After adding the user id, you can remove "Administrators" from the trusted groups. This is to prevent other Windows Administrators, other than the user id that you trust, from modifying the settings. For the details, you may refer to
https://support.secureaplus.com/what-are-trusted-groups-and-trusted-users/