How to find where an image is used by it’s url

I’m trying to do some optimization on a third party wordpress, and found that some images that are from a cdn are actually taking some time to load, so I would like to modify the post/page/etc where it is being used to point to the same server instead, however I don’t know how to pinpoint in which type of element this image is being used, how can I go about it? if it worth something, the page seems to be using a theme called DIVI

Thank you.