XSLT: Insert node in XML document

This is how you can insert a new node somewhere in an XML document using XSLT.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
       
  <!-- Identity template, copies everything as is -->
  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()"/>
    </xsl:copy>
  </xsl:template>

  <!-- Override for target element -->
  <xsl:template match="targetNode">
    <!-- Copy the element -->
    <xsl:copy>
      <!-- And everything inside it -->
      <xsl:apply-templates select="@* | *"/>
      <!-- Add new node (or whatever else you wanna do) -->
      <xsl:element name="newNode"/>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>