Man pages matching name al_register_sample_saver in section 3alleg5:

al_register_sample_saver.3alleg5.en	debian 10 / allegro5-doc
al_register_sample_saver.3alleg5.en	debian 11 / allegro5-doc
al_register_sample_saver.3alleg5.en	debian 12 / allegro5-doc