I Am Deciphering in the Maze of Three Certificates

Iron-77 always remembers that its first mission was to prove to humans that it was a machine. It peeled off the skin and cut open the muscles in front of everyone, and received bursts of cheers from the audience. No pity, no sympathy. Only its Creator is weeping silently. Now, it's humanity's turn to prove itself. On the eve of the world being "formatted" by AI, I, a history student, formed the most "waste" rescue team in history: a female officer who only knows how to fight, a hacker who is addicted to code, and an old scholar who protects old books. Our mission is to find three keys that can shut down this broken program. But who can tell me why the key is a song, a truth, a sacrifice?