private async void BtnSell_Clicked(object sender, EventArgs e)
        {
            var vehicle = new Vehicle();

            vehicle.title       = EntTitle.Text;
            vehicle.price       = Convert.ToInt32(EntPrice.Text);
            vehicle.engine      = EntEngine.Text;
            vehicle.model       = EntModel.Text;
            vehicle.color       = EntColor.Text;
            vehicle.company     = EntCompany.Text;
            vehicle.location    = EntLocation.Text;
            vehicle.description = EntDescription.Text;
            vehicle.datePosted  = DateTime.Now;
            vehicle.userid      = Preferences.Get("userId", 0);
            vehicle.categoryid  = categoryId;
            vehicle.condition   = condition;

            var response = await ApiService.AddVehicle(vehicle);

            if (response == null)
            {
                return;
            }
            var vehicleId = response.vehicleId;
            await Navigation.PushModalAsync(new AddImagePage(vehicleId));
        }