How to keep namespace attributes in XML element?

Summary

How to keep namespace attributes in XML element?

Content

Hi Everyone,

We have a requirement to build a XML file and place in FTP location.

I'm able to build XML without the namespace attributes.

Could you please advise how to keep namespace attributes in XML element?

Expected XML file:

<xml version="1.0" encoding="UTF-8" ?>

<inv:Invoice xmlns:inv="http://npp.com/ERPInvoice&quot; xmlns:ns1="http://npp.com&quot; xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance&quot;>
   ..............
  </inv:Invoice>

Regards,

Karthick.R

Version

20.1.3.0.0

Code Snippet

<xml version="1.0" encoding="UTF-8">
<inv:Invoice xmlns:inv="http://npp.com.qa/ERPInvoice" xmlns:ns1="http://npp.com.qa" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <InvoiceHeader>
      <invoiceType>Invoice</invoiceType>
      <invoiceDate>2020-05-12</invoiceDate>
      <invoiceNumber>18001</invoiceNumber>
      <invoiceAmount>10000<invoiceAmount>
   </InvoiceHeader>
  </inv:Invoice>