How to share memory buffer from WASM with JS?

 public unsafe void WriteToSink()
 {
     _inner.RenderInterleaved(_buffer);
     fixed(float* p = _buffer)
     {
         Interop.PostAudio((nint)p, _buffer.Length);
     }
 }

exports = await getAssemblyExports("MyPitch.Browser.dll");
export function postAudioData(data, length) {
    var memory = exports.memory;
    console.log(memory) //undefined?
    var floatData = new Float32Array(memory, data, length).slice();
    player.feed(data);
    console.log(JSON.stringify(floatData))
}

    [JSImport("postAudioData", "Interop")]
    public static partial void PostAudio(
        nint buffer, int length
    );