internal class WsFederationAuthCleanupMiddleware
{
    private readonly RequestDelegate _next;

    public WsFederationAuthCleanupMiddleware(RequestDelegate next)
    {
        _next = next ?? throw new ArgumentNullException(nameof(next));
    }

    public Task Invoke(HttpContext context, IAuthorizationService authorizationService)
    {
        var request = context.Request;
        // could look for a specific path as well...
        if (request.Query.TryGetValue("wa", out var wa) && wa == "wsignoutcleanup1.0")
        {
            // Your signin scheme probably cookies
            request.HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
            return Task.CompletedTask;
        }

        return _next(context);
    }
}