You'll need to generate a point for each line of text, add the text with a LabelPointReplacer or TextAdder, potentially style it with the PDFStyler and then place that on the page using a PDFPageFormatter. Those points don't need to be in any specific coordinate system, it can be arbitrary, just keep in mind that the PDFPageFormatter will scale them all to fit within the box.

Keep in mind you can only have one text style per text object. So a single line of text with one word bold is actually 3 separate text objects. Aligning those properly is going to be a major hassle.