Hi @chaimpaperman,
There is no native way to do that in the platform currently , but it's in our roadmap and coming very soon.
We have a couple of workarounds, that @tylerlamparter detailed few days ago in a post with similar requirements :
https://connective.celigo.com/t/fetching-base64-from-an-image-url-in-celigo/289
Hope that helps.
Let us know if you have questions.