Author here, I tested it with this PDF of a handwritten doc [1], and it converted both pages accurately.
1. https://github.com/pnshiralkar/text-to-handwriting/blob/mast...
1. https://github.com/pnshiralkar/text-to-handwriting/blob/mast...
FYI, your GitHub link tells me it's unable to render because the pdf is invalid.