Adobe Signature Field Not Recognized

Which product are you using?
PDF.js Express Plus

PDF.js Express Version

Detailed description of issue
I have a signature field I added to a PDF through Adobe Acrobat Pro. The PDF Express WebViewer does not recognize this as a signature field with the “SignHere” tag. Is this not supported in PDFJS?

Expected behaviour
WebViewer should display SignHere tag on signature field and allows for digital signature to be added.

Does your issue happen with every document, or just one?
Every document


Code snippet

JavaScript PDF Viewer Customize Forms Demo
Customize Form Style Demo for PDF Viewer
    path: '../../lib', // path to the PDF.js Express'lib' folder on your server
    licenseKey: 'Insert free license key here',
    initialDoc: 'Affirmation Form Fields.pdf',
    config: 'config.js'
    // initialDoc: '/path/to/my/file.pdf',  // You can also use documents on your server
  }, document.getElementById('viewer'))
  .then(instance => {

    // disable annotations

    // now you can access APIs through the WebViewer instance
    const { Core, UI } = instance;

    // adding an event listener for when a document is loaded
    Core.documentViewer.addEventListener('documentLoaded', () => {
      console.log('document loaded');

    // adding an event listener for when the page number has changed
    Core.documentViewer.addEventListener('pageNumberUpdated', (pageNumber) => {
      console.log(`Page number is: ${pageNumber}`);

Hello ekaleida,

Can you provide a file to test with?
Thank you!

Best regards,