One key not functioning

MacbookPro 13” 2012, A1278. The P key has stopped functioning, this happened whilst the macbook was shutdown. It is the only key that doesn’t work. I have tried all the software type items and settings including reseting PRAM which was said to use the P without any of the OS settings. I have removed the key cap, used a soft brush and blown with air. The little silicon rubber covered button presses but the key still doesn’t function. Is there anything more I can try? Are individual keys replaceable or is it the whole keyboard? I replaced trackpad a few years ago so have the tools to dismantle it. The other option is to use a bluetooth keyboard.