the xsl stylesheet I use is

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
    <xsl:output method="xml"/>
    <xsl:param name="idAplicatie">kubera</xsl:param>
	<xsl:template match="*|@*|text()">
		<xsl:copy>
			<xsl:apply-templates select="*|@*|text()"/>
		</xsl:copy>
	</xsl:template>
	<xsl:template match="/">
		<xsl:processing-instruction name="xml-stylesheet">href="https://localhost:8443/exist/rest//db/xsltforms/xsltforms.xsl" type="text/xsl"</xsl:processing-instruction>
		<xsl:copy>
			<xsl:apply-templates select="*|@*|text()"/>
		</xsl:copy>
	</xsl:template> 
    <xsl:template match="idAplicatie/text()">
		<xsl:value-of select="$idAplicatie"/>
    </xsl:template>
</xsl:stylesheet>