To deploy you client code and assets to the Client project area, you can use the deploy command:
bm client deploy <path to local project>
Your "path to local project" will point at the folder containing the files and assets you wish to deploy to the remote service. It is good practice to be in your current project folder when using deploy.
Once deployed, your changes will be instantly available at your project URL.
Note: The Client CLI tool will only upload files that have changed since the last deploy.