Getting Signature is invalid. on Starting zoom meeting

Meeting SDK
1

I am using Meeting SDK 2.18.2.

Created the meeting with oauth/token after create the meeting i am trying to start the meeting but it showing Signature is invalid.

I am crate the signature by the below code.

public static string GenerateJWTAppToken(string apiKey, string apiSecret, string meetingNumber, string ts, string role)
{
char padding = { ‘=’ };
string message = String.Format(“{0}{1}{2}{3}”, apiKey, meetingNumber, ts, role);
apiSecret = apiSecret ?? “”;
var encoding = new System.Text.ASCIIEncoding();
byte keyByte = encoding.GetBytes(apiSecret);
byte messageBytesTest = encoding.GetBytes(message);
string msgHashPreHmac = System.Convert.ToBase64String(messageBytesTest);
byte messageBytes = encoding.GetBytes(msgHashPreHmac);
using (var hmacsha256 = new HMACSHA256(keyByte))
{
byte hashmessage = hmacsha256.ComputeHash(messageBytes);
string msgHash = System.Convert.ToBase64String(hashmessage);
string token = String.Format(“{0}.{1}.{2}.{3}.{4}”, apiKey, meetingNumber, ts, role, msgHash);
var tokenBytes = System.Text.Encoding.UTF8.GetBytes(token);
return System.Convert.ToBase64String(tokenBytes).TrimEnd(padding);
}
}