How to download PDF automatically using js?

It is also possible to open the pdf link in a new window and let the browser handle the rest:

window.open(pdfUrl, '_blank');

or:

window.open(pdfUrl);

Use the download attribute.

var link = document.createElement('a');
link.href = url;
link.download = 'file.pdf';
link.dispatchEvent(new MouseEvent('click'));