What is meant by Mushaf Fatimah, and is it a mushaf different from the Muslims' agreed-upon mushaf?

There is no Quranic codex named "Mushaf Fatima" among the printed Qurans, and the circulated Qurans are those transmitted by the Companions from the Messenger of Allah, peace be upon him. The claim that there is a codex belonging to Fatima that contains more than what is found in the current Qurans is refutable, because Fatima did not live long after the Prophet, peace be upon him, and she was not known to transmit much knowledge during that period. Furthermore, Ali ibn Abi Talib, may Allah be pleased with him, did not narrate anything that contradicts the Quran we possess. Additionally, some of those to whom this codex is attributed deny its existence.