
admin.appserverSetDefaultUser( config as element(configuration), appserver-id as (Number|String), value as (Number|String) ) as element(configuration)
This function sets the default user (for use with application-level authentication) in the configuration for the specified App Server.
http://marklogic.com/xdmp/privileges/admin/app-server-security
http://marklogic.com/xdmp/privileges/admin/app-server-security/{id}
http://marklogic.com/xdmp/privileges/admin/group-security
http://marklogic.com/xdmp/privileges/admin/group-security/{id}
  
  const admin = require('/MarkLogic/admin.xqy');
  const config = admin.getConfiguration()
  const groupid = admin.groupGetId(config, "Default")
  admin.appserverSetDefaultUser(config,
         admin.appserverGetId(config, groupid, "myAppServer"),
	 xdmp.eval('
                  
                  const admin = require('/MarkLogic/admin.xqy');
		    at "/MarkLogic/security.xqy";
	          sec.uidForName("annabelle")', (),
	   <options xmlns="xdmp.eval">
		 <database>{xdmp.securityDatabase()}</database>
	   </options>))
   //returns the new configuration element -- use admin.saveConfiguration
   //to save the changes to the configuration or pass the configuration
   //to other Admin API functions to make other changes.