function convertHtmlToPdf() {
      const element = document.getElementById('incidentReport');
      const headerContent = generateHeaderContent(); // Get the header content

      var reportPageHeight = $('#incidentReport').innerHeight();
      var reportPageWidth = $('#incidentReport').innerWidth();

      var pdf = new html2pdf(element, {
          margin: [45, 10, 10, 10],
          pagebreak: { mode: 'avoid-all' },
          html2canvas: { scale: 1 },
          image: { type: 'png', quality: 1.0 },
          jsPDF: {
              unit: 'pt',
              format: [reportPageWidth, reportPageHeight],
              orientation: 'landscape',
          }
      }).set(headerContent).save('IncidentReport.pdf');
  }

  function generateHeaderContent() {
      const startDate = $('#startDateIncident').val();
      const endDate = $('#finDateIncident').val();
      const todayChecked = $('#todayIncident').is(':checked');
      const dateRange = todayChecked ? 'Today' : (startDate + ' to ' + endDate);

      const header = ` <div style="display: flex; align-items: center; margin-bottom:20px;">
  <div style="margin-left:40px;">
      <img src="/app-assets/images/logo/logo-color3.png" alt="Logo" style="max-height: 40px;">
  </div>
  <div style="font-size: 12px; margin-left:180px;">Date: ${dateRange}</div>
  </div> `;

      return header;
  }

Troubleshooting Header Absence in ASP.NET’s html2pdf Generated PDF

I attempted to include a header in a PDF generated using html2pdf in ASP.NET. I expected the header to be visible in the generated PDF document, but despite setting it up correctly, it did not appear.