IntersectionObserver and ajax loaded content

I am working on website at the moment, that has some native lazy loading of images using IntersectionObserver the images that I am trying to load are loaded in via ajax as a result I don't think they are "loaded" into DOM on page load, and therefore the images cannot be lazyloaded, by lazy load codes looks like this,

const io = new IntersectionObserver((entries, observer) => {
    // console.log(entries)
    entries.forEach(entry => {
      console.log('😍');

      if (entry.isIntersecting) {

        console.log('intersecting');

        const img = entry.target;
        const src = img.getAttribute('data-lazy');

        img.setAttribute('src', src);
        img.classList.add('fade');

        observer.disconnect();
      }
    });

Is it possible to lazy load images that are part of content that is loaded via ajax?