rateLogoutUrl(
    Auth0OidcLogoutRequest request) {
  final queryParams = &lt;String, String&gt;{
    &#39;client_id&#39;: request.clientId,
  };

  if (request.idTokenHint != null &amp;&amp; request.idTokenHint!.isNotEmpty) {
    queryParams[&#39;id_token_hint&#39;] = request.idTokenHint!;
  }

  if (request.postLogoutRedirectUri != null &amp;&amp;
      request.postLogoutRedirectUri!.isNotEmpty) {
    queryParams[&#39;post_logout_redirect_uri&#39;] = request.postLogoutRedirectUri!;
  }

  if (request.sta