How to clear the segment selection in Xamarin.Forms SegmentedControl?

..
        <buttons:SfSegmentedControl 
                x:Name="segment"
                SelectionTextColor="White"
                HeightRequest="80"
                VisibleSegmentsCount="6"
                Color="Transparent" 
                BorderColor="Black"
                SelectedIndex="1"
                FontColor="Black"
                BackgroundColor="Transparent" >
            <segmentCollection:List x:TypeArguments="x:String">
                <x:String>RedMi</x:String>
                <x:String>oppo</x:String>
                <x:String>vivo</x:String>
                <x:String>ipad</x:String>
                <x:String>realme</x:String>
                <x:String>Nokia</x:String>
            </segmentCollection:List>
        </buttons:SfSegmentedControl>
        <Button Text="Button" Clicked="Button_Clicked" WidthRequest="150"/>
..

private void Button_Clicked(object sender, EventArgs e)
        {
            segment.SelectedIndex = -1;
        }