The change password feature only applies to those sites that are not using Azure Active Directory integration i.e. those sites that use the https://portal.docassembler.com.au address, rather than the https://portal2.docassembler.com.au address. In this case passwords are managed by the Harbour Software server.
In order to change your password select Change Password from the Admin menu.Enter your existing password into the Old Password box and then your new password into both the New Password and Confirm Password boxes. Ensure that your new password matches the criteria detailed, then click the Submit Change button.