How to use HummusJS operators to adjust text space?

Question

HummusJS is a great lib make pdf for node js.

but I can't understand how to use operators like TJ.

How to use text, hex or code on it?

I have try it as like as example

var newPdf = new hummus.PDFWStreamForFile('temp.pdf');
var pdfWriter = hummus.createWriter(newPdf);
var page = pdfWriter.createPage(0, 0, 595, 842);
var pageContent = pdfWriter.startPageContentContext(page);
    pageContent.BT()
       .k(0,0,0,1)
       .TJ('H',3,'ES')
       .Tm(30,0,0,30,78.4252,662.8997)
       .ET();

but It doesn't work.

thanks help