I'm configuring the DXAdvanced series advanced security model (/AS1). When registering a system administrator in the user registration screen, it only lets me set the "Default Password." How can I set my own password?

In the user registration screen, first set the default password.
The first time you log in, enter the default password.
The message, "Your password has expired. Key in your new password" appears, and you can enter a new password.
For more information, see section 2.2, "Logging In and Out" in the advanced security function (/AS1) user's manual.