add staging key

Signed-off-by: Maurice Preuß <hello@envoyr.com>

src/Id/AnikeenId.php

@@ -66,6 +66,11 @@ class AnikeenId
      */
     private static string $refreshTokenField = 'anikeen_id_refresh_token';
 
+    /**
+     * Anikeen ID environment mode.
+     */
+    protected static ?string $mode = null;
+
     /**
      * Guzzle is used to make http requests.
      */
@@ -110,7 +115,7 @@ class AnikeenId
         if ($redirectUri = config('services.anikeen.redirect')) {
             $this->setRedirectUri($redirectUri);
         }
-        if (config('services.anikeen.mode') === 'staging') {
+        if (self::getMode() === 'staging') {
             self::setBaseUrl(self::$stagingBaseUrl);
         }
         if ($baseUrl = config('services.anikeen.base_url')) {
@@ -141,6 +146,11 @@ class AnikeenId
         return self::$accessTokenField;
     }
 
+    public static function getMode(): string
+    {
+        return config('services.anikeen.mode', 'production');
+    }
+
     public static function useRefreshTokenField(string $refreshTokenField): void
     {
         self::$refreshTokenField = $refreshTokenField;