Writing Heads (2013)

They are the first and the last, those who imagine stories and give voice to the characters who live them. However, they never speak. But now, they emerge from the shadows of a poorly lit room and tell their secrets, their tricks, their influences; they tell their own story, that of those who face the blank page, the absolute nothingness; that of those who are the true authors, those who create and destroy entire universes. They are the screenwriters.

Unfortunately the movie Writing Heads is not yet available on HBO Max.