Is there a prayer called the “grave-light” (kabir-nur) prayer?

There is no narration that the Prophet (peace be upon him) or his companions performed a prayer called the “kabir-nur prayer.” Therefore, performing a prayer with this specific intention is an innovation (bid‘ah). However, a person may perform as many voluntary (nafl) prayers as they wish at any time, and in the supplication afterward, they may seek refuge in Allah from the torment and evils of the grave. Indeed, our Prophet (peace be upon him) recommended seeking refuge in Allah from the torment of the grave in supplication. (Bukhari, Janaiz, 86-87 [1372-1377])

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu