MudBlazor: how to switch Dark/Light theme?

I try to use it for Dark/Light theme switch . The question is: I have made it on one page, it works, but how to do : I add switch to the component Settings.razor and the selected theme is using for all pages and after restart too? Now it works on one page only. The code as in the doc

<MudThemeProvider @bind-IsDarkMode="@_isDarkMode" Theme="_theme" /><MudSwitch @bind-Checked="@_isDarkMode" Color="Color.Primary" Class="ma-4" T="bool" Label="Toggle Light/Dark Mode" />@code { private bool _isDarkMode;}