@RaghavenderReddyL

By using Pega OOTB activity you will not be able to enable password for PDF. 

You can make use of below mentioned java code to enable password. Attached screenshot how you can include java in activity and how parameter and local variable needs to be configured.

In PDFStream parameter you need to have your file stream content.

In RW and Masterpassword parameter you need to have your password value.

If you don't want master password, then leave that parameter empty.

In Output_PDFStream parameter you will have your final password enabled PDF File stream.

In pyAttachAsPDF activity, next to HTMLToPDF activity step you can place this java code logic.

Java Code:

byte[] pdfByteData = Base64Util.decodeToByteArray(PDFStream); PDFDocument = pdfByteData; org.apache.pdfbox.pdmodel.PDDocument doc=null;   org.apache.pdfbox.pdmodel.encryption.AccessPermission ap=null;   org.apache.pdfbox.pdmodel.encryption.StandardProtectionPolicy spp=null;   String MasterPassword = tools.getParameterPage().getString("MasterPassword");   String RWPassword = tools.getParameterPage().getString("RWPassword"); //Get the byte array of original PDF (transferred from Param->Local Variable in previous step).       byte[] byteArray=(byte[]) PDFDocument;       java.io.ByteArrayInputStream bis=null;         bis = new java.io.ByteArrayInputStream(byteArray);         try {           doc=org.apache.pdfbox.pdmodel.PDDocument .load( bis );           ap=new org.apache.pdfbox.pdmodel.encryption.AccessPermission();           ap.setCanAssembleDocument(false);         ap.setCanExtractContent(false);         ap.setCanExtractForAccessibility(false);         ap.setCanFillInForm(false);         ap.setCanModify(false);         ap.setCanModifyAnnotations(false);         ap.setCanPrint(true);         ap.setCanPrintDegraded(false);         spp=new org.apache.pdfbox.pdmodel.encryption.StandardProtectionPolicy( MasterPassword, RWPassword, ap);           doc.protect(spp);           java.io.ByteArrayOutputStream out = new java.io.ByteArrayOutputStream();           doc.save(out);           PDFDocument=out.toByteArray(); // Replace old byte array with newly generated one.       }       catch(Exception e) { throw new PRRuntimeException(e); }       finally {         if (bis!=null) {           try { bis.close(); }           catch(Exception e) { throw new PRRuntimeException(e); }   }       if(doc!=null) {         try { doc.close(); }         catch(Exception e) { throw new PRRuntimeException(e); }       }       } byte[] byteArray_1=(byte[]) PDFDocument;

PDFProcessesDocument = Base64Util.encodeToString(byteArray_1);