Currently you can stream The Wolfpack with Hulu and with Hoopla. If you already have a Hulu subscription then you won't need to pay anything extra to stream this documentary.
If you don't have access to Hulu or Hoopla then you can buy or rent The Wolfpack to watch online via a number of digital platforms including FandangoNOW, Redbox, VUDU, Google Play Movies and YouTube. You can rent the documentary for as little as $2.99 and you can buy the documentary for as little as $9.99.