You still need to make an account to watch anything on IMDB TV on Prime Video or anything on Prime Video, but here's the 411, this movie is now on IMDB TV and it's free to watch.
What a weird streaming/broadcast licensing journey this movie is. From MGM's Epix, to Universal Kids, to two channels of Derpibooru's least favorite media conglomerates and now Amazon's IMDB TV. Still not either on Netflix or Dfam, but that kinda doesn't bother me anyway.