Material design wpf icon button doesn't dock to right

So, I'm trying to create a list with 'delete' button on the right side
I have this code:

<ListBox.ItemTemplate>
    <DataTemplate>
        <DockPanel LastChildFill="False">
            <TextBlock DockPanel.Dock="Left" Text="{Binding Name}" FontSize="14"/>
            <Button DockPanel.Dock="Right" Style="{StaticResource MaterialDesignIconForegroundButton}">
                <md:PackIcon Kind="Close" Height="16" Width="16"/>
            </Button>
        </DockPanel>
     </DataTemplate>
</ListBox.ItemTemplate>

Result

So, how can I dock the button to the right?

This is because your data template lies inside the ListBoxItem, whose template has its alignment property set to be bound to the ListBox's ContentAlignment.

So you need to set HorizontalContentAlignment="Stretch" on the list box itself. Or, as more general solution, override the whole template of the ListBoxItem.