Using next image, you can supply a src prop. This image url will be used to generate a bunch of srcset sizes appropriately, and finally when next image renders the <img> tag, it will put the largest srcset resulted image (for example width 3840px) as the value of the outputted src attribute within the <img> tag.

Is it possible to change which size next image selects to use as the fallback here? This will most likely only affect old browsers and crawlers etc.