The book of the 3 Maccabees is found in most Orthodox Bibles as a part of the Anagignoskomena, while Protestants and Catholics consider it non-canonical, except the Moravian Brethren who included it in the Apocrypha of the Czech Kralicka Bible. It is also included in the Armenian Bible.
The book actually has nothing to do with the Maccabees or their revolt against the Seleucid Empire, as described in 1 Maccabees and 2 Maccabees. Instead it tells the story of persecution of the Jews under Ptolemy IV Philopator (222-205 BC), some decades before the Maccabee uprising. The name of the book apparently comes from the similarities between this book and the stories of the martyrdom of Eleazar and the Maccabeean youths in 2 Maccabees; the High Priest Shimon is also mentioned.
Read more about 3 Maccabees: Synopsis, Authorship and Historicity