What is the ruling on the prayer known as "al-Salat al-'Azimiyyah" (the Magnificent Prayer), which is recited collectively and aloud after the five daily prayers, Friday prayers, funeral prayers, and during the burial of the deceased, given its known text?

Committing to sending blessings upon the Prophet in this specific form and manner, and dedicating specific times for it, falls under the category of innovation (Bid‘ah). It is obligatory to advise the one who does so and to explain that this is not from the guidance of the Prophet (peace be upon him), nor his Companions, nor the Successors.