Is the mentioned plea for forgiveness attributed to Abdullah ibn al-Sultan, with its story and virtues, authentic and transmitted from the Messenger, may Allah bless him and grant him peace, or was it fabricated by someone?

The aforementioned istighfar (seeking forgiveness) is fabricated and falsely attributed to the Messenger of Allah, peace and blessings be upon him. It is not permissible to ascribe it to him or to narrate it, except for the purpose of warning against it and clarifying its fabrication. Evidence of its fabrication includes its absence from the recognized collections of Sunnah (definition) and the fact that no Companion with this name is known. If its virtues were true, its mention would have been widespread. Therefore, one should restrict oneself to the authentic and narrated forms of istighfar. It is also important to avoid reading booklets that contain such fabricated hadiths, and to be cautious when perusing any book, verifying the authenticity of its content by presenting it to trustworthy scholars.