How to add image upload in Xaml

This is my Xaml code .How do i add an image upload in this form.

` < StackLayout>

    <Grid x:Name="gridLayout" HorizontalOptions="FillAndExpand">

        <Grid.RowDefinitions>

            <RowDefinition Height="50"/>

            <RowDefinition Height="50"/>

            <RowDefinition Height="150"/>

            </Grid.RowDefinitions>

        <Grid.ColumnDefinitions>

            <ColumnDefinition Width="130"/>

            <ColumnDefinition Width="*"/>

        </Grid.ColumnDefinitions>

            <Label Text="Expense Category" Grid.Row="0" Grid.Column="0"/>

            <Entry x:Name="cateoryName" Text="{Binding ExpenseCategory}" Grid.Row="0" Grid.Column="1"/>

            <Label Text="Expense Code" Grid.Row="1" Grid.Column="0"/>

            <Entry x:Name="expCode"  Text="{Binding ExpenseCode}" Grid.Row="1" Grid.Column="1"/>

            <Label Text="Description" Grid.Row="2" Grid.Column="0"/>

            <Editor  x:Name="descrip" BackgroundColor="WhiteSmoke"  Grid.Row="2" Grid.Column="1"/>


    </Grid>

    <Button x:Name="btnSave" Text="Save" FontSize="Large" BackgroundColor="DodgerBlue" TextColor="White" Clicked="OnSave" Margin="1"/>

</StackLayout>`