online pass invalid

I have mass effect 3, that I bought new a few years ago for the ps3. I tried playing multiplayer since I bought the game and I have never been able to use my online pass that comes in the box. Not to mention the bonus n7 defender armor and valkyre assault rifle. This has been going on for years now, and I gave up, but now I really want to play multiplayer and I hope you guys can help me solve this. How can I play multiplayer? It says my pass is invalid.