When are children taught the ruling on shaving pubic hair as one of the practices of Fitra (natural inclination)?

The child must be taught the ruling on shaving pubic hair as he approaches puberty, either by directly teaching him or by giving him a book or a pamphlet that addresses the rulings of puberty, while reminding him of the meaning of religious accountability (taklif shar'i), the rights of Allah, the duties of the accountable person, and the rulings of ghusl al-janabah (ritual bath after sexual impurity).