بسم الله الرحمن الرحيم
Yes, it is mandatory to make qaza of all the fardh or wajib (witr) prayers and all the fardh fasts which you missed after calculating them; otherwise it shall remain due on you. It is not enough to make taubah and pay fidyah.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.