[HELP] Siren Settings Value Help

I am trying to get the siren settings value for a custom fire truck in the fivem server, which I am close with the owner, changed. We have edited the carvariations.meta to for the firetruck. But it is still not working. What are we missing?
I have tried doing so on vanilla GTA with a custom non-replacement vehicle, but an add-on vehicle. I changed the settings and was able to get it to work. But with FiveM I am stuck on how to get it to work properly.
This is only for the siren sounds. I already have a client sided siren pack installed. But the firetruck add-on units have the same siren sound as a police car. The “Firetruk” and “Police” have different siren sounds even in vanilla GTA.