First, build your image, e.g.: docker build -t zb2o ..
If your cloud uses a different CPU architecture than your development
machine (e.g., you are on a Mac M1 and your cloud provider is amd64),
you'll want to build the image for that platform, e.g.:
docker build --platform=linux/amd64 -t zb2o ..
Then, push it to your registry, e.g. docker push myregistry.com/myapp.
Consult Docker's getting started docs for more detail on building and pushing.