<telerik:RadSideDrawer x:Name="drawer" HandlerChanged="drawer_HandlerChanged"
                       DrawerLength="200">
        <telerik:RadSideDrawer.MainContent>
            <Grid>
                <Label Text="Main content" />
            </Grid>
        </telerik:RadSideDrawer.MainContent>
        <telerik:RadSideDrawer.DrawerContent>
            <VerticalStackLayout Spacing="10"
                             Padding="10, 10, 0, 0">
                <Button Text="Mail" />
                <Button Text="Calendar"/>
                <Button Text="People" />
                <Button Text="Tasks" />
            </VerticalStackLayout>
        </telerik:RadSideDrawer.DrawerContent>
    </telerik:RadSideDrawer>

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
    }

    private void drawer_HandlerChanged(object sender, EventArgs e)
    {
        this.UpdateDrawer();
    }

    private void UpdateDrawer()
    {
        var platformView = this.drawer.Handler.PlatformView;

# if IOS || MACCATALYST
        var platformSideDrawer = (TelerikUI.TKSideDrawerView)platformView;
        var drawer = platformSideDrawer.SideDrawers[0];
        drawer.Style.HeaderHeight = 0;
        drawer.Style.FooterHeight = 0;
#endif
    }
}