If it's a historical biopic about Wyatt Earp, did they go back in time and bring him in for a cameo? How did this happen?

About the legendary lawman Bass Reeves, one of the greatest frontier heroes and one of the first Black deputy U.S. marshals west of the Mississippi River.

But he doesn't die. He returns to his former profession of lawman to hunt down his lynchers and bring them to justice.