private async void Submit_Clicked(object sender, EventArgs e)
{
FeedbackModel feedback = new FeedbackModel();
var uid = await _firebaseAuth.GetCurrentUser();
// Get input
feedback.Key = "00";
feedback.Subject = subject.SelectedItem.ToString();
feedback.Body = body.Text;
feedback.Date = DateTime.Today.Date.ToString();
feedback.Status = false;
feedback.UserUID = uid;
_firebaseDatabase.SubmitFeedback(feedback);
await Navigation.PopAsync();
}