add route to search instances by field value

src/ElixForms/Auth/ElixFormsAuthenticationClient.php

@@ -9,7 +9,7 @@ class ElixFormsAuthenticationClient {
     private $baseUrl;
     private $httpClient;
 
-    public function __construct(string $baseUrl, Client $httpClient = null) {
+    public function __construct(string $baseUrl, ?Client $httpClient = null) {
         $this->baseUrl = rtrim($baseUrl, '/');
         $this->httpClient = $httpClient ?? new Client(['timeout' => 10.0, 'http_errors' => false]);
     }