The error org.xml.sax.SAXParseException: Content is not allowed in prolog usually indicates that there is some content before the XML prolog in the file you are trying to parse.
You can use the addCData() method of the SimpleXMLElement class to add a CDATA section to an XML element.
You can remove a child element with a specific attribute in SimpleXML for PHP using the xpath() function.
To convert a SimpleXml object to a string in PHP, you can use the asXML() function.
This error message typically occurs when there is additional content or characters after the closing root element in an XML document.