What is the Sacred Congregation of Indulgences?
Do you mean the Apostolic Penitentiary?
New Catholic Dictionary:
Congregation of Indulgences and Relics
Created by Pope Clement IX, 6 July 1669. Pope Pius X united it to the Congregation of Rites, 28 January 1904. The congregation was established to do away with any chance of abuses in the matter of indulgences and sacred relics. It received the faculty of settling every difficulty which might arise regarding the relics of saints and indulgences, if such difficulty did not pertain to a dogma of faith. The congregation had the right and duty of correcting, without the form of trial, any abuses which might arise or be found concerning indulgences and relics, of forbidding the publication of false and indiscreet indulgences, of examining those already published, and, after submitting the case to the pope, of rejecting unworthy ones by his authority. It was to examine and verify newly-found relics, and also to exercise prudent moderation in granting indulgences and distributing relics.