Hedy (1966)

Egotistical faded star Hedy Lamarr visits a plastic surgeon to be transformed into the "14-year-old girl" she believes herself to be. She is then caught shoplifting by Mary Woronov and is put on trial, with Tavel as the judge and her five ex-husbands the jury. Hedy remains self-centered and detached throughout, posing and primping and bursting out renditions of "I Feel Pretty" and "Young at Heart."

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