Getting unknown character while generate pdf through coffeescript

I need to generate pdf/a file using node js. I found one library that will generate pdf/a file in CoffeeScript which is converted to node js.

I am able to convert that pdf/a file successfully. but now I am now facing issue with the font while generating pdf/a. It's giving me a weird font.

I am using below file for generating table into pdf, https://github.com/giuseppe-santoro/pdfkit/blob/208726a271f01a7bd6ea178950ab5ad9cf04cdef/test.coffee

Data I write to pdf :

data = [
  { code: '0001', name: 'Black table', quantity: '10', price: '$ 19.20' }
  { code: '0005', name: 'White table', quantity: '8',  price: '$ 19.20' }
  { code: '0012', name: 'Red chair',   quantity: '40', price: '$ 12.00' }
]

while I generate pdf I am getting below output.

!"#$ %&'$ ()&*+,+- ./,0$
+++++++++$1+2+&34$ 56 72589:6 : ;<,+$2+&34$ = 72589:6 > ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966
665: ?$#20<&,/ @6 725:966