valuesRepository.cs

public async Task DeleteById(int Id)
{
    using (SqlConnection sql = new SqlConnection(_connectionString))
    {
        using (SqlCommand cmd = new SqlCommand("DeleteValue", sql))
        {
            cmd.CommandType = System.Data.CommandType.StoredProcedure;
            cmd.Parameters.Add(new SqlParameter("@Id", Id));
            await sql.OpenAsync();
            await cmd.ExecuteNonQueryAsync();
            return;
        }
    }
}