LuaTest.cs

using LuaInterface;
using UnityEngine;

public class LuaTest : MonoBehaviour
{   
    private Lua         mLua;
    private LuaFunction mLuaFunction;

    private void Start()
    {
        var filename = Application.dataPath + "/luaTest.lua";

        mLua = new Lua();
        mLua.DoFile( filename );
        mLuaFunction = mLua.GetFunction( "update" );
    }
    
    private void Update()
    {
        mLuaFunction.Call( Time.deltaTime );
    }
}