My unlock button does not work on my key fob, doesn’t illuminate at all. All other buttons work. I have to unlock the car with the key but every time the alarm goes off. I don't have a spare fob that I can test it with.

 

Try replacing the battery in the fob.

 

Get another fob and get it registered with the security system, it's nuts to only have one.
Then once you have something that works you can try cleaning the contacts or otherwise fixing the fob you have, but maybe just get a replacement and have both working ones married to the car at the same time. That's the expensive part of key/fob replacement.

 

clean the contacts on the fob? The fob can’t be disassembled unless I am missing something

 

https://rennlist.com/forums/diy-caye...-fob-case.html

Before doing that I might pull the battery and blast a ton of contact cleaner in there. Deoxit preferably. But as you say that button is dead the underlying switch might not just be dirty or corroded but has failed. Who knows?