https authentication using Haskell

I'm trying to write a haskell program that accesses a https url, where a file is automatically downloaded. The site requests authentication. I tried using the Req library but I couldn't understand all the web and networking concepts.

Can anyone give me some template code or at least to tell me more precisely where i can find the functions I need?

This is the code I wrote so far, but is'n not working:

import Control.Monad
import Control.Monad.IO.Class
import Data.Aeson
import Data.Default.Class
import Data.Maybe (fromJust)
import Data.Monoid ((<>))
import Data.Text as T
import GHC.Generics
import Network.HTTP.Req
import qualified Data.ByteString.Char8 as B

main = runReq def $ do
    let myMethod = GET
        myUrl = https $ T.pack "https://..."
        myBody = NoReqBody
        myProxy = ignoreResponse
        myOption = basicAuth (B.pack "user") (B.pack "password")
    m <- req myMethod myUrl myBody myProxy myOption
    return ()