You can format different sections of invoice by setting format of that the section. You can set this format information directly in data file or using the function setInvoiceFormatSettings(). For example if you want to format date as "d-m-y", or add prefix/suffix to quantity column, you can do this using this function.
$xinvoice = new Xinvoice();
/**
* Set format settings of invoice sections
* @param string $section section of invoice
* @param string $subsection sub section of invoice (optional)
* @param bool $format set format of section true to show, false to hide
* return object Object of xinvoice
*/
// hide complete header
$xinvoice->setInvoiceFormatSettings("header","",false);
//hide from(Sender) "name" not complete "from"(sender)
$xinvoice->setInvoiceFormatSettings("from","name",false);
echo $xinvoice->render();