Why is [CascadingParameter] public HttpContext? HttpContext { get; set; } always null?

[ManrajPatel]

In my web app (Blazor Web App with Server rendering) I am using duende identity server and have closely followed the implementation from eShop app.

While everything is working fine, I am stuck at logout. I am using the same Logout implementation from eShop but in my code I always get null for HttpContext in the following code.

[CascadingParameter]
public HttpContext? HttpContext { get; set; }

private Task LogOutAsync()
    => LogOutService.LogOutAsync(HttpContext!);  

Can someone please guide what am I missing here?