Man pages matching name al_load_ttf_font_stretch in section 3alleg5:

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