jsPDF Set the Opacity of Text Color inside PDF Document

<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.5.3/jspdf.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf-autotable/3.2.3/jspdf.plugin.autotable.min.js"></script>
<script>
  function demoPDF() {
let doc = new jsPDF()

doc.saveGraphicsState();
doc.setGState(new doc.GState({opacity: 0.2}));
doc.text("SIR JOHN WILLIAMSON LATHAM IS THE CAPTAIN OF NEW ZEALAND", x, y, {align: 'center', baseline: 'middle'})
doc.restoreGraphicsState();

  doc.save("output.pdf");
};

demoPDF();
</script>