There is no one definitive answer to this question - it depends on what format you prefer and what specific content you're looking for. However, here are some potential options:
-The National Association for the Advancement of Colored People (NAACP) offers a "livestream" on their website of live events related to black lives matter: https://www.naacp.org/latest/live-stream/
-Blavity, a black-owned media company, has compiled a list of "11 must-watch black lives matter documentaries": https://blavity.com/11-black-lives-matter-documentaries
-Colorofchange.org, "the nation's largest online racial justice organization", also has a page dedicated to black lives matter resources, including TV shows, films, and books: https://colorofchange.org/blacklivesmatter/
Ultimately, there are many ways to learn about and support the black lives matter movement - watching documentaries or Livestreams is just one possible option.