Xamarin Shell FlyoutItem's tab click event - xamarin.forms

Question

Im using Xamarin forms, and on my AppShell, i want 2 tabs, i want to have a clicked event on one of the tabs, so that when clicked on it doesnt load another page but actually execute a function (show an Rg.Popup on top of the current page).
So i need a way to capture the tab clicked event or maybe a command or anything.
here is what i have:
<FlyoutItem FlyoutDisplayOptions="AsSingleItem" IsVisible="False">
<Tab Title="001">
<ShellContent ContentTemplate="{DataTemplate local:HomePage}"></ShellContent>
</Tab>
<Tab Title="002">
<ShellContent ContentTemplate="{DataTemplate local:ProfilePage}"></ShellContent>
</Tab>
</FlyoutItem>

Answer 1

1 year too late but hope this helps. you can use menuItem which will display ontop of flyoutitem
<MenuItem Text="item" StyleClass="MenuItemLayoutStyle" Clicked="OnClickMethod">
</MenuItem>

Answer 2

Create a class inherit from TabBar and override the method OnPropertyChanged:
public class MyTab : TabBar
{
protected override void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
if (propertyName == "CurrentItem")
{
int index = this.Items.IndexOf(this.CurrentItem);
if(index == 0)
{
}
if(index == 1)
{
}
}
}
}
Use it in Xaml
<local:MyTab>
<Tab Title="Browse" Icon="tab_feed.png" x:Name="tab1">
<ShellContent ContentTemplate="{DataTemplate local:ItemsPage}" />
</Tab>
<Tab Title="About" Icon="tab_about.png">
<ShellContent ContentTemplate="{DataTemplate local:AboutPage}" />
</Tab>
</local:MyTab>
Another way I thought is that you can execute the function in the page's OnAppearing method.