AMEN." are found in the vast Majority of all Greek texts, including E, G, K, L, W, Delta, Pi, Sigma, as well as in four copies of the Old Latin (k, f, g, and q), which point to a Bible text that predates anything we have in the Greek copies.
All these words are also found in the ancient Syriac Peshitta, Harclean, Curetonian, and Palestinian, as well as the Coptic Boharic and Sahidic, the Georgian, Armenian, Gothic, Slavonian, and Ethiopian ancient versions.
Even a big name modern day Bible agnostic like John Mac Arthur (who himself does not really believe that ANY Bible IS the inerrant words of God) comments on these words: "The doxology is simply this; “For Thine is the kingdom, the power, the glory forever, Amen.” That’s a doxology.
You just say it, you just think it, you just offer it to God, you don’t dissect it.
Just sharing this great skit wherein the Archbishop of Canterbury endorses a Cockney version of the Bible. Hello Dad Up there in good ol’ heaven Your name is well great and holy and we respect you guv!