mitmweb -s main.py Does not show anything in Command Prompt

[Kagenokao]

It says No such Script when ran.

[Dontmindthehacker]

did you download main.py

[Dontmindthehacker]

go to http://mitm.it/ instead.

[Ill-tableflip-U]

go to http://mitm.it/ instead.

and do what? i am confused on how to get mitmproxy and run it. i installed and configure the proxy settings, but i am not too sure on what else to do