Is the opening supplication, “Allah is the Greatest, the Great, and praise is to Allah, much, etc.,” specific to voluntary prayers only?

Question:
May Allah reward you. Honorable Shaykh, this questioner asks: Is the opening supplication, “Allah is the Greatest, the Great, and praise is to Allah, much,” and so on, recited in the obligatory prayers, or only in the voluntary ones?

Answer:
The takbirat al-ikram is "Allahu Akbar" only, and nothing is added to it. It is called the takbir, not "Subhan Allah Akbar." One says the takbirat al-ikram, "Allahu Akbar," and then comes the opening supplication (istiftah). Various forms of the istiftah are reported from the Prophet (peace and blessings be upon him), the most authentic and most frequent of which is: "Subhanaka Allahumma wa bihamdika, tabarakta wa ta'ala, la ilaha ghayruk." Then one seeks refuge with Allah from the accursed Shaytan, says "Bismillah al-Rahman al-Rahim," and recites Surat al-Fatihah. In his late-night prayer (tahajjud), when he said, "O Allah, Lord of Jibril, Ismail, and Israel, , guide me to the truth in which there is disagreement by Your permission. Indeed, You guide whom You will to a straight path," this too was reported from the Prophet (peace and blessings be upon him) in his late-night prayer.
. Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him) has independent treatises explaining the types of opening supplications reported from the Prophet (peace and blessings be upon him) , which are printed separately and also printed in the collected works.