FireBaseHelper.cs

public async Task AddPerson(int personId,string name)  
        {  
  
            await firebase  
              .Child("Persons")  
              .PostAsync(new Person() { PersonId=personId, Name = name });  
        }  
  
private async void BtnAdd_Clicked(object sender, EventArgs e)  
        {  
            await firebaseHelper.AddPerson(Convert.ToInt32(txtId.Text), txtName.Text);  
            txtId.Text = string.Empty;  
            txtName.Text = string.Empty;  
            await DisplayAlert("Success", "Person Added Successfully", "OK");  
            var allPersons = await firebaseHelper.GetAllPersons();  
            lstPersons.ItemsSource = allPersons;  
        }