GreyKey (2019)

Fear and fascination arise in Muriel Grey when she remembers the figure of her father, who passed away when she was still very young. Thirty years after his death, Muriel will tell us the story of José Carlos Grey, a Black Holocaust survivor, freedom fighter in the Spanish Civil War and the French Resistance, and one of the only Black men known to have been imprisoned at the Mauthausen concentration camp in Austria.

Unfortunately the movie GreyKey is not yet available on HBO Max.