private async void TokenButton_OnClicked(object sender, EventArgs e)
{
TokenHandler th = new TokenHandler();
string token = await th.GetToken();
TextBox.Text = token;
}
private async void DeviceIdButton_OnClicked(object sender, EventArgs e)
{
TokenHandler th = new TokenHandler();
string deviceId = await th.GetDeviceId();
TextBox.Text = deviceId;
}