You see this page of the Add Server Instance wizard when you specify domain details to register an instance of the GlassFish application server or Sun Java System Application Server. Use this page of the wizard to specify the username and password to use to login as domain administrator.
You are not required to supply a domain admin username and password when registering a server instance. If you do not supply a username and password when registering an instance, you are prompted to supply a username and password when needed.
In this page of the wizard you can supply the following information: