this.encryptForRecipients is not a function

Hi all

I have a JavaScript as below that keeps returning TypeError: this.encryptForRecipients is not a function. Any Ideas ?

JavaScript

   var thePermissions = {
                         allowAll: false,
                         allowAccessibility: false,
                         allowContentExtraction: false,
                         allowChanges: "none",
                         allowPrinting: "none"
                     };
                   

var theUserEntity = {
                         firstName: "The",
                         lastName: "User",
                         fullName: "The User",
                        
                     };
                  

var sh = security.getHandler( "Adobe.PPKMS" );
var dir = sh.directories[0];
var dc = dir.connect();

var theGroup = { userEntities: [ theUserEntity ], permissions: thePermissions };

 
this.encryptForRecipients( { oGroups: [theGroup], bMetaData: true } );