How do I remap 'Enter' and 'P' keys on a damaged MacBook Air keyboard?

Hello! About a year ago I spilled coffee on my keyboard, it was unable to get fixed in time so now certain keys like 'Enter' and the letter 'P' and other keys like '?' and '\' will not work and I have to use a keyboard viewer on the screen. This makes typing very annoying but I can't get a new MacBook. I am looking for a way to remap at least the enter key and the 'p' key as those are what I need most. If you know of a software or app or anything so that I can create a new shortcut for these keys, I'd appreciate any support or suggestions!! Thank you!!

[Re-Titled by Moderator]