There are 5 different versions of this text
A few different versions are on audiobook on youtube.
The Greek one says Moses wrote it. Not all of them have the 5500 year prophecy only some do. I assume it was in the original. When Gospel of Nicodemus says Pilate went into the temple, and the Judeans opened a 70 book bible (the 70 books were the books outside the normal canon only for the wise mentioned in 2 Esdras 557-457 BC), and says the first book had a 5500 year prophecy until the messiah it could be referencing Life of Adam, and Eve meaning that was the first book or actually I believe the first book was 1 Enoch, and it originally contained that 5500 year prophecy which has since been lost.
A few different versions are on audiobook on youtube.
The Greek one says Moses wrote it. Not all of them have the 5500 year prophecy only some do. I assume it was in the original. When Gospel of Nicodemus says Pilate went into the temple, and the Judeans opened a 70 book bible (the 70 books were the books outside the normal canon only for the wise mentioned in 2 Esdras 557-457 BC), and says the first book had a 5500 year prophecy until the messiah it could be referencing Life of Adam, and Eve meaning that was the first book or actually I believe the first book was 1 Enoch, and it originally contained that 5500 year prophecy which has since been lost.