// standard PDF conversion request:

https://api.pdflayer.com/api/convert

    ? access_key = YOUR_ACCESS_KEY
    & document_url = http://url.com/invoice.html  
    & header_text = MyHeader
    & watermark_url = http://url.com/watermark.png

// choose from 50+ customization parameters 
// and create your perfect PDF

// Instantiate the class
$html2pdf = new pdflayer();

// Set parameters
$html2pdf->set_param('document_html', $html_code);
$html2pdf->set_param('header_text', 'My Heading');

// Convert PDF
$html2pdf->convert();
$html2pdf->display_pdf();