Aftermarket key fob programming trouble

Hey all, I just got this aftermarket key fob, in hope that i could program it to my 1999 integra ls. The key fob is brand new, so i know it’s not the battery. I’ve tried to program it the way the instructions told me to, by doing the turn it to the run pos. click lock and turn it off and repeat 3 times, but it didn’t seem to work. I don’t really need the alarm to work, I just want the remote to lock and unlock the car. Some things that might help to know:

1. I don’t have a horn
2. my passenger door lock switch does not work but it locks and unlocks fine with the driver side switch

Is there a fuse or something i could check? I had done some research but i have gotten different answers, 1. Check for the “brain” now i’ve heard it’s in different locations but i have only checked underneath the driver seat in which it is not there. That’s all I got. Thanks!