react expert finalise webpack configuration

I have a project (just demo hello world) in react working fine.

I have a branch of the project with a webpack configuration working ok with hello world page, but needs some config to use with real project webpage.

So I need an expert to finalise the webpack for my react project.

the project also uses express to catch URL data incoming. myurl.com?data="my passed data in url"

now I need to get rid of express so I can pack with webpack,
the data that was provided by express URL, now I want to have it as a global variable...

So when I load my page I inject the window variable and change that global variable.