Host is not allowed to connect to this mysql database

using Microsoft.AspNetCore.SignalR;
using System.Threading.Tasks;
using System;
using MySql.Data;
using MySql.Data.MySqlClient;
using probagetrequest.Models;

namespace SignalRChat.Hubs
{
    public class ChatHub : Hub
    {

        public async Task SendMessage(string user, string message)
        {
            string connn = "Server=localhost;Database=DBChatApp;user id=sa;password=xxx";
            MySqlConnection con = new MySqlConnection(connn);
            try { 
            Console.WriteLine("Connecting to MySql...");
            con.Open();
            string cmddd = "INSERT INTO Messages (Username,Message) VALUES (@Usernamee,@Messagee)";
            MySqlCommand cmd = new MySqlCommand(cmddd, con);
            cmd.Parameters.Add("@Usernamee", MySqlDbType.VarString).Value = user;
            cmd.Parameters.Add("@Messagee", MySqlDbType.VarString).Value = message;
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc.ToString());
            }
            con.Close();
            Console.WriteLine("Done!!!!!");

            Console.WriteLine($"user={user}, message={message}");
            await Clients.All.SendAsync("ReceiveMessage", user, message);
        }
    }
}