Per the example project in the source, you can reference fonts on the local system with the following:
PdfFont ArialNormal = new PdfFont(Document, "Arial", FontStyle.Regular, true);
Contents.DrawText(ArialNormal, NoteSize, NoteX, NoteY0, "text goes here");
If you install this Barcode font you should be able to reference it in the same way. Note: you may want to close Visual Studio, install the font, then reopen (or reboot) to ensure you're referencing the updated font list.