Is it permissible to perform the prostration of recitation (Sajdat al-Tilawah) while seated on a chair when reading the Qur’an from a computer, or is it a condition to prostrate on the ground?

Whoever is able to prostrate naturally, their prostration by nodding is not valid. The one who is unable should nod, based on the hadith: "When you prostrate, enable your forehead to touch the ground." And the hadith: "Pray on the ground if you are able, otherwise, nod." Ibn Umar said: "If a sick person is unable to prostrate, he should nod with his head." Complete prostration is placing the seven limbs on the ground, based on the hadith: "I have been commanded to prostrate on seven bones: the forehead - and he pointed with his hand to his nose - the hands, the knees, and the ends of the feet."