After reviewing my work I would like to retract this statement:

I found this example in the docs

"some/image.jpg"
|> Image.open!()
|> Image.resize!(200)
|> Image.stream!(suffix: ".jpg", buffer_size: 5_242_880)
|> ExAws.S3.upload("images", "some_object_name.jpg")
|> ExAws.request()

and with some refactoring it got me where I wanted to be.

In short, I was doing something wrong with the file path, and because of that it wasn’t reachable, so I misinterpreted the errors.

Thanks anyway for the quick responses @LostKobrakai and @kip.

Glad you’re up and running. And it prompted me to fix that example which should be (and is now on hexdocs.pm):

"some/image.jpg"
|> Image.thumbnail!(200)
|> Image.stream!(suffix: ".jpg", buffer_size: 5_242_880)
|> ExAws.S3.upload("images", "some_object_name.jpg")
|> ExAws.request()