Thanks to charlynancy  for this tuto

Downlaod TCPDF Library and install it
Duplicate a template for editing file
Edit item.php and load modular code

Use this code after

<?php
<!-- EOF item title -->
 endif;
?>

this

<?php
//allow to load a flexicontent field
$myfield_html = FlexicontentFields::getFieldDisplay($item, 'field_resume');
 

// Include the main TCPDF library (search for installation path).
require_once JPATH_LIBRARIES . '/tcpdf/tcpdf.php';
 
// create new PDF document
$pdf = new TCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);
 
// remove default header
$pdf->setPrintHeader(false);
 
// set footer fonts
$pdf->setFooterFont(Array(PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA));
 
// set default monospaced font
$pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);
 
// set margins
$pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP, PDF_MARGIN_RIGHT);
$pdf->SetFooterMargin(PDF_MARGIN_FOOTER);
 
 
// set auto page breaks
$pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
 
// set image scale factor
$pdf->setImageScale(PDF_IMAGE_SCALE_RATIO);
 
// set font
$pdf->SetFont('dejavusans', '', 10);
 
// add a page
$pdf->AddPage();
 
// create some HTML content
$html = '<h1>HTML Example</h1>
<div>your content</div>
<div style="text-align:center">blabla

more content
//here display a flexicontent field_resume
</div>' . $item->fields['field_resume']->display;

 
// output the HTML content
$pdf->writeHTML($html, true, false, true, false, '');
 
// reset pointer to the last page
$pdf->lastPage();
 
//Close and output PDF document, save pdf in /images/
$pdf->Output($_SERVER['DOCUMENT_ROOT'] . 'SOUS_REPERTOIRE/images/' . $this->item->alias . '.pdf', 'F');
//becaurefull adapt the good folder to your config 'SOUS_REPERTOIRE/images/'
//ex 'SOUS_REPERTOIRE/images/'
//complet url /var/www/default/SOUS_REPERTOIRE/images
 
// Now we will add a link to the pdf
echo '<a target="_BLANK" href="/images/' . $this->item->alias . '.pdf"><strong>PDF</strong></a>';
?>