First download the corresponding language font from Google fonts or any other source and save it in your server path.
Then add the name of custom font and the urls pointing to files of custom font to pdfMake.fonts
property
pdfMake.fonts = { 'yourfontname': { normal: url to normal font, bold: url to bold font, italics: url to italics font, bolditalics: url to bolditalics font } }
Finally add the name of the custom font to the defaultStyle property of document definition of whole document.
defaultStyle: { //add the name of our custom font here. font: 'yourfontname' },
In our example we have used the Google korean font to export korean language from ParamQuery grid