Token in JsonFormat

Question

Hi

In below code i want to get token & what is the best option to save that token

public class AccessToken
{
public string access_token { get; set; }
public string token_type { get; set; }
public long expires_in { get; set; }
}
private static async Task<string> GetToken()
{
string credentials = String.Format("{0}:{1}", clientId, clientSecret);
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(credentials)));
List<KeyValuePair<string, string>> requestData = new List<KeyValuePair<string, string>>();
requestData.Add(new KeyValuePair<string, string>("grant_type", "client_credentials"));
FormUrlEncodedContent requestBody = new FormUrlEncodedContent(requestData);
var request = await client.PostAsync("https://accounts.spotify.com/api/token", requestBody);
var response = await request.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<AccessToken>(response);
}
}

Thanks