During Salat when going from one posture to another like from Qiyam to Ruku to Qiyam to Sujud, do we have to say Takbir "Allahu Akbar" behind the Imam?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. It is reported in a sound Hadith that the Prophet (Sallallahu Alaihi wa Sallam) said: Pray as you have seen me pray . [Reported by Imam al-Bukhari ]. It is reported from Ibn Masoud that he said: The Prophet (Sallallahu Alaihi wa Sallam) used to say Takbir in every bowing, raising, standing and sitting . [ al-Tirmizi said, Ibn Masoud 's Hadith is sound, and knowledgeable people act in accordance with it, including Abu Bakr , Umar and their followers]. The four Imams of schools of thought are agreed upon that pronouncing Takbir is confirmed Sunnah. al-Malikiyah and al-Shafiyah consider it Sunnah Muakkadah while al-Hanabilah and al-Ahnaf consider it an obligation. However, the meaning in the end is the same. The ruling is common for an Imam or his followers, but a follower in a congregational prayer does not need to make two prostrations of forgetfulness if he forgets pronouncing Takbir. Allah knows best.