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
A physicist whose work on black-body radiation led to Planck's law and the use of the Planck constant. He received the 1918 Nobel Prize in Physics.[ref]
Max Planck by Lorenz Friedrich Beck. Biographical account: theoretical-physics appointments, radiation work, 1858 birth and 1947 death
Portrait of Max Planck
. Unknown photographer; Nationaal Archief / gahetna.nl source recorded on Commons. Public domain (anonymous historical photograph, as declared on Commons). Source and usage information on the linked Wikimedia file page. Source.
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.