Is here anyone that know how to add custom sirens to your fiveM server (not client side). I want to add this sirens to my server (https://sv.gta5-mods.com/vehicles/swedish-siren)
I dont know if its possible to have server side sirens but I somebody know pls let me know 
As far as I know and I’ve tried many ways to make it work server sided, it didn’t work. I came up with some information where FiveM still doesn’t support custom sounds to be server sided. Although, there is no information if it will be ever supported or not in future.
Am replying in case he stills wonder. The link you sent, works only for guns and not all of them. Sirens aren’t supported. Also, the custom sounds for guns can be heard only by you, others are hearing the default one. I’ve put it to the test with 10-15 players and everyone was hearing default gun shots from other players but when they tried it by themselves, they heard the custom sounds. When it comes to the sirens, the sirens remain the default one, no matter what you do. So, that release is not 100% accurate to what it states in the forum discussion.
Been talking and discussing this matter with other owners of servers, some big, some small but they also confirmed what I’ve said before, FiveM doesn’t support custom sounds to be streamed.
I have somehow managed to get server side sirens working (but very buggy). And it was a complete accident, one of my police bikes when you first turn on ELS it plays the British Siren but the audio keeps cutting out. Turning the siren off and back on makes it go back to the default siren! It is 100% the british siren however. I’ll still need to look more into it but it’s really weird. (I have no client-side mods on at all and happens to everyone, others can also hear it) The model has no files related to audio
Updates?
Your welcome…
doesnt work