Referencing this answer (refrencing)

Just use await and make sure to return doc inside the callback

something like this

var doc = new jspdf.jsPDF({
  orientation: 'p',
  unit: 'pt',
  format: 'letter'
});


var field = "<b>html test </b>";
doc.text(10, 10, "test");
//add first html
await doc.html(field, {
  callback: function (doc) {
    return doc;
  },
  width: 210,
  windowWidth: 210, 
      html2canvas: {
          backgroundColor: 'lightyellow',
          width: 210, 
          height: 150
      },
      backgroundColor: 'lightblue', 
  x: 10,
  y: 50,
  autoPaging: 'text'
});
window.open(doc.output('bloburl'));

now you can call doc.html as many times as you want for that same document

Originally posted by @bakuur in https://github.com/parallax/jsPDF/issues/3074#issuecomment-1328427528