How do I trigger downloads?

I have an image node selected. My plugin gets the image data, sends it to an API of mine which returns new image data. I want to trigger the downloading of that data. I’m at a loss since I can only find this sentence in the docs: “This can be useful if you want to download the image or upload it somewhere else.” I can’t find anywhere that actually says how to trigger a download.

Check out this thread: Proper way to save exports on the computer.