Man pages matching name al_remove_opengl_fbo in section 3alleg5:

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