Where should HttpContext.Response.Redirect("~/") go?

Question

I'm a bit confused about the ~ path in Asp.NET 6.x

Assume my Web site is hosted on IIS at: http://somesite.org/special/

I'm using Carter Lib but I don't think that should matter.

    public LogoutModule()
    {
        Get("/api/admin/logout", async ctx =>
        {
            await ctx
               .SignOutAsync("Cookies")
               .ConfigureAwait(false);

            ctx.Session.Clear();
            ctx.Response.Redirect("~/");
        });
    }

I thought the redirect would go to http://somesitename.org/special but instead it goes to:

http://somesitename.org/special/api/admin/~/

Redirecting using ctx.Response.Redirect("/"); doesn't work either. It then goes to:

http://somesitename.org/

In general I don't know the virtual directory this site is hosted in. I thought the ~ operator took care of that. What don't I understand here?