jsPDF v 2.5.1

const pdf = new jsPDF('p', 'pt', 'a4');

  pdf.html('<h1>How to Train Your Dragon</h1>', {
    callback: function (doc) {
      pdf.save(`${journal.name}.pdf`);
    },
    autoPaging: 'text',
    jsPDF: pdf,
    windowWidth: 600,
    width: 600
  });
  

The output in the PDF is “Howto Train Your Dragon”. Note the missing space between the words “How” and “to”.

https://github.com/parallax/jsPDF/issues/3742