Why GetSpectrumData can't work on Lua in Unity

Unity Engine
1

This is the code
I use Lua to write code on unity but why this code can’t run?

if   audioSource.audio.isPlaying    then

        spectrum = audioSource.audio:GetSpectrumData(1024, 0, UnityEngine.FFTWindow.BlackmanHarris);   
          for i = 0,64,1 do
                        myintensity = sqrt(spectrum[i])
                        cubes[i].transform.position = UnityEngine.Vector3((0.15*i)-6,-2,5)
                        cubes[i].transform.localScale = UnityEngine.Vector3(0.15,4*myintensity,1)
                        cubes[i].renderer.material.color = UnityEngine.Color(2*myintensity, .4, .9)
         end
end
2

Unity doesn’t support Lua.