Looks like the docker part definitely worked 
Now you have an issue with the static files not loading. I believe this is because the PUBLIC_URL parameter does not work with the development mode. This is mentioned in the readme here: https://code.onehippo.org/cms-community/bloomreach-spa-sdk/tree/bloomreach-spa-sdk-14.1.0/examples/react-csr. You can try either running the prod build npm build or use this hack mentioned here with the homepage attribute in package.json https://github.com/facebook/create-react-app/issues/1487