Script to download view-only permission file from google drive.

runner.js

let jspdf = document.createElement("script");
 
jspdf.onload = function () {
 
    let pdf = new jsPDF();
    let elements = document.getElementsByTagName("img");
    for (let i in elements) {
        let img = elements[i];
        console.log("add img ", img);
        if (!/^blob:/.test(img.src)) {
            console.log("invalid src");
            continue;
        }
        let can = document.createElement('canvas');
        let con = can.getContext("2d");
        can.width = img.width;
        can.height = img.height;
        con.drawImage(img, 0, 0);
        let imgData = can.toDataURL("image/jpeg", 1.0);
        pdf.addImage(imgData, 'JPEG', 0, 0);
        pdf.addPage();
    }
 
    pdf.save("download.pdf");
};
 
jspdf.src = 'https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.5.3/jspdf.debug.js';
document.body.appendChild(jspdf);

Step by step:
1. Open the document in Google Docs
2. Scroll to the bottom of the document, so all the pages are present
3. Open Developer Tools on separate window and choose the Console tab
4. Paste the code below (and hit enter)

Ref: https://codingcat.codes/2019/01/09/download-view-protected-pdf-google-drive-js-code/