Redirect everything to my fiddler reverse proxy

I'm behind a corporate proxy, I'd like to install some dependancies usis "pip" or "npm" from nodeJS but it won't work (obviously).

I solved this problem for a lot of thing by setting a reverse proxy on http://localhost:8888/ with fiddler.

Now each thing I made work had a proxy option so I just had to input this.

How can I redirect everything through this reverse proxy?

Thanks.