quoteinvestigator.com/2017/09/25/progress/ on Quote Investigator says it appeared in 1948. Can't easily check, but will believe it for now.
Published as Scientific Autobiography and Other Papers by Max Planck translated by Frank Gaynor (1949) which also contained other papers.
This section refers just to the translation of Scientific autobiography by Max Planck (1948).
The Planck's law paper.
Articles by others on the same topic
Max Planck was a German theoretical physicist best known for his role in the development of quantum theory, which revolutionized the understanding of atomic and subatomic processes. He was born on April 23, 1858, and died on October 4, 1947. In 1900, Planck introduced the idea that energy is quantized, proposing that electromagnetic energy could be emitted only in discrete quantities, or "quanta.