How to update locally-created Docker image

I have a Docker image that is in the fly.io registry. I currently deploy from it. I’d like to update it so that it has a few added programs but can’t find a way to do this. Any idea?

do you have the original Dockerfile used to create the image? you can build a new image version locally with a new version tag (registry.fly.io/your-app:new-version, or similar) and then use fly auth docker and docker push to push the new version.

I don’t. I migrated here from Glitch and it seemed to automatically find and provision the image. I can’t say where out how it all worked, to be honest