Look back to where we started the Ubuntu container with docker run. There’s a -v parameter there which “mounts” your code directory from the host into the container, making it available in the container as /working. This means that /working inside the container is the same directory as your code directory on the host. If you edit a file there inside the container, those edits will show up from the host's perspective too.
So the ZIP file you create inside the container in /working will automatically appear in the code directory on the host, and you can simply upload it to AWS from there.