fs.stat error on converting pdf to Image using npm pdf-image package

Question

I am trying to convert a pdf to image in frontend using javascript using this https://www.npmjs.com/package/pdf-image package.

export const Convertpdf2img = async() => {
    var pdfImage = new PDFImage('./dummy.pdf');
    pdfImage.convertPage(0).then(function (imagePath) {
        // 0-th page (first page) of the slide.pdf is available as slide-0.png
          const ans = fs.existsSync("./dummy.png") // => true
    },function(err){
        console.log(err);
    });
}

The error I am getting is this - TypeError: fs.stat is not a function

My dummy file is in the same folder where this function is written.