The Messenger of Allah ﷺ only performed the qunut for one month, supplicating after the bowing.
حدثنا وكيع حدثنا هشام عن قتادة
إنما قنت رسول الله ﷺ شهرا يدعو بعد الركوع
Its isnad is sahih. It was mentioned previously at 12091.