title: PDFLib.js field.constructor.name return "t" after build
body: <p>I'm trying to fill pdf form usinf PDFLib js.
  In my localhost it works fine but after deployment &quot;field.constructor.name&quot; return &quot;t&quot; type. and the data is no filled.
  there is no error, but nothing happened.</p>
  <pre><code>    const pdfDoc = await PDFDocument.load(formPdfBytes);
  
          // Register the `fontkit` instance
          pdfDoc.registerFontkit(fontkit);
  
          // Embed our custom font in the document
          const customFont = await pdfDoc.embedFont(fontBytes, { subset: true });
  
          // Get the form containing all the fields
          const form = pdfDoc.getForm();
          const fields = form.getFields()
          fields.forEach(field =&gt; {
          //HERE THE PROBLEM!!
  
          const type = field.constructor.name // GOT &quot;t&quot;
          const name = field.getName();
  </code></pre>