Xamarin custom renderer take photo

Question

I want to take photo using Xamarin form custom renderer. I use Custom Renderer Sample and I add a Button named 'btnTakePicture' in Xaml , but I don't have any idea how to take photo on Button click event. I want to show camera in part of screen. Also I checked Xam.Media.Plugin and I couldn't take photo.

Xaml Code

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
             xmlns:local="clr-namespace:CustomRenderer;assembly=CustomRenderer"
             x:Class="CustomRenderer.frmCamera"
             Title="Main Page">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="1*"/>
            <RowDefinition Height="7*"/>
            <RowDefinition Height="2*"/>
        </Grid.RowDefinitions>
        <Grid Grid.Row="0">
            <Label Text="Camera Preview"/>
        </Grid>
        <Grid Grid.Row="1">
            <local:CameraPreview Camera="Rear" x:Name="cmrPreview"
                             HorizontalOptions="FillAndExpand"
                             VerticalOptions="FillAndExpand"  Background="black"/>
        </Grid>
        <Grid Grid.Row="2">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="1*"/>
                <ColumnDefinition Width="1*"/>
            </Grid.ColumnDefinitions>
            <Button x:Name="btnChangeCamera" Text="Switch Camera" Clicked="btnChangeCamera_Clicked"/>
            <Button x:Name="btnTakePicture" Text="Take" Grid.Column="1" Clicked="btnTakePicture_Clicked"/>
        </Grid>
        <Frame></Frame>
    </Grid>
</ContentPage>

C# Code

using System.IO;
using Xamarin.Essentials;
using Xamarin.Forms;

namespace CustomRenderer
{
    public partial class frmCamera : ContentPage
    {
        public frmCamera()
        {
            InitializeComponent();
        }

        private void btnChangeCamera_Clicked(object sender, System.EventArgs e)
        {
            if (cmrPreview.Camera == CameraOptions.Rear)
                cmrPreview.Camera = CameraOptions.Front;
            else
                cmrPreview.Camera = CameraOptions.Rear;

        }

        bool blnIsFlashLight = false;
        private void btnFlashLight_Clicked(object sender, System.EventArgs e)
        {
            if (blnIsFlashLight)
            {
                Flashlight.TurnOffAsync();
                blnIsFlashLight = false;
            }
            else
            {
                Flashlight.TurnOnAsync();
                blnIsFlashLight = true;
            }
        }

        private void btnTakePhoto_Clicked(object sender, System.EventArgs e)
        {

        }
    }
}

here is my project Screenshot