Question: Is it possible to change Referer which PhotoSwipe sends to host when loading images?

[sullivan-2]

Is it possible by modifying app code to manually set Referrer which PhotoSwipe sends in request headers to host when downloading images?

I don't know JavaScript well, but could try finding solution if you advise the place in PhotoSwipe code where images downloading maintained.

[dimsemenov]

You may use contentLoadImage event.

lightbox.on('contentLoadImage', ({ content, isLazy }) => {
  console.log(content.element);
});

If you wanna look how it works internally, the code is at

PhotoSwipe/src/js/slide/content.js

Line 121 in beb4810

loadImage(isLazy) {