Is the Imam's supplication and the congregants' saying "Amin" after every prayer considered an innovation (bid'ah) in the Hanafi school of thought, and how can those who do so be advised and convinced that it is an innovation?

It was not transmitted from the Prophet, peace and blessings be upon him, nor from the righteous predecessors, that the Imam should supplicate and the congregants say 'Amin' after the obligatory prayers. Rather, what is established is the well-known remembrance (dhikr), seeking forgiveness (istighfar), and declaring God's greatness (tahlil). The Companions used to know that the Prophet's prayer had concluded by the pronouncement of 'Allahu Akbar' and the raising of voices in remembrance. Sheikh Al-Islam Ibn Taymiyyah views that persistence in this supplication is an innovation (bid'ah), as the Prophet, peace and blessings be upon him, did not do it, and had he done it, the Companions would have transmitted it. Some jurists from the Hanafi school considered it desirable after the Fajr and Asr prayers, or after all prayers, without raising the voice except for teaching purposes. However, they have no Sunnah to support this. Ibn Al-Qayyim said: It is impossible for the Prophet, peace and blessings be upon him, to have consistently performed it without it being transmitted from him. Therefore, adhering to this supplication is an innovation, and Imams should be advised to clarify the Sunnah of the Prophet, peace and blessings be upon him, and that acts of worship are based on divine texts and established practice.