Currently Jean-Michel Basquiat: The Radiant Child is streaming on Kanopy and Prime Video. If you already have a subscription for these services then you won't need to pay anything extra to stream Jean-Michel Basquiat: The Radiant Child.
If you don't have a Prime Video or Kanopy subscription you can buy or rent Jean-Michel Basquiat: The Radiant Child via platforms like Microsoft Store, Apple iTunes and Google Play Movies for as little as $2.99.