error: undefined reference to 'SandInlineHook'

[Arc157]

Hello, im getting this error error: undefined reference to 'SandInlineHook' everytime i declare SandInlineHook like this in my c++ main file. SandInlineHook((void*)WeaponSounds, (void*)old_WeaponSounds);. These are my variables

bool WeaponSoundsHookInitialized = false;
bool isShotgun;

And this is the function that i wanna hook

void(*old_WeaponSounds)(void *instance);
void WeaponSounds(void *instance) {
    if(instance != NULL) {
        if(!WeaponSoundsHookInitialized){
            WeaponSoundsHookInitialized = true;
        }
        if (isShotgun) {
            *(bool *) ((uint64_t) instance + 0x3A8) = true;
        }
    }
    old_WeaponSounds(instance);
}

I have no idea what could be causing this error. I'm using the nativehook library.