private async Task <string> TakeUserIdByAccessToken() { var access_token = await HttpContext.GetTokenAsync("access_token"); string userId = ""; if (string.IsNullOrEmpty(access_token)) { userId = "Unauthorized"; } // ------- Extract userId (sub) from access token string accessTokenString = new JwtSecurityTokenHandler().ReadJwtToken(access_token).ToString(); string toBeSearched = "\"sub\":\""; userId = accessTokenString.Substring(accessTokenString.IndexOf(toBeSearched) + toBeSearched.Length); userId = userId.Substring(0, userId.IndexOf("\"")); return(userId); }