dapper invoke stored procedure to get return value

DapperInvokeSp.cs

        public string GetPassword(string accountId)
        {
            using (var connection = new SqlConnection("my connection string"))
            {
                var password = connection.Query<string>("spGetUserPassword", new {Id = accountId},
                    commandType: CommandType.StoredProcedure).SingleOrDefault();

                return password;
            }
        }