AWS Cognito revoke apple login

Question

5.1.1 Legal: Privacy - Data Collection and Storage

• Apps that offer Sign in with Apple should use the Sign in with Apple REST API to revoke user tokens.

REST API to revoke user tokens doc https://developer.apple.com/documentation/sign_in_with_apple/generate_and_validate_tokens/

I am getting "invalid client" or "invalid_grant" in the error response.

 const client_secret = await getClientSecret();
 const token = await authToken(authCode,client_secret);
 await revokeToken(refreshToken, client_secret);
 async function authToken(authCode, client_secret) {
  const data = querystring.stringify({
    code: authCode,
    client_id: "****",
    client_secret: client_secret,
    grant_type: "authorization_code",
  });
  var config = {
    method: "post",
    url: "https://appleid.apple.com/auth/token",
    headers: {
      "Content-Type": "application/x-www-form-urlencoded",
    },
  };
  try {
    const response = await axios.post(config.url, data, {
      headers: config.headers,
    });
    return response.data.refresh_token
  } catch (err) {
    return err.response.data.error;
  }
}

 async function getClientSecret() {
  const privateKey = fs.readFileSync("key/path");
  return jwt.sign(
    {
      iss: "****",
      iat: Math.floor(Date.now() / 1000),
      exp: Math.floor(Date.now() / 1000) + 360000,
      aud: "https://appleid.apple.com",
      sub: "****",
    },
    privateKey,
    {
      algorithm: "ES256",
      header: {
        alg: "ES256",
        kid: "***",
      },
    }
  );
 }