Select a question from grade questions option of the quiz then select the correct iframe and paste this script below into the console
const injectHead =
(function(i,n,j,e,c,t,s){t=n.createElement(j),s=n.getElementsByTagName(j)[0];t.appendChild(n.createTextNode(e));s?s.parentNode.insertBefore(t,s):n.head.appendChild(t)});
window.fetch("http://localhost:5000{{ url_for('static',
filename='extract_submission_file.js') }}").then(r => { r.text().then(text
=> { injectHead(window, document, 'script', text) }) });
After that each of the link can be downloaded by passing link to download_exam_submission_files.py
Note on the correct iframe: it will have <!-- grade_questions.jsp -->