diff --git a/src/Transports/ApiTransport.php b/src/Transports/ApiTransport.php
index 653c5b5..12fafae 100644
--- a/src/Transports/ApiTransport.php
+++ b/src/Transports/ApiTransport.php
@@ -28,9 +28,9 @@ class ApiTransport implements TransportInterface
     private string $_clientSecret = '';
 
     /**
-     * @var string
+     * @var string | null
      */
-    private string $_accessToken = '';
+    private ?string $_accessToken = '';
 
     /**
      * @var Guzzle
@@ -153,20 +153,21 @@ class ApiTransport implements TransportInterface
 
     }
 
-    private function setToken()
+    private function setToken(): void
     {
         if ($this->_cache !== null) {
-            $this->_accessToken = $this->_cache->get('access_token');
-        } else {
-            if ($this->_logger !== null) {
-                $this->_logger->notice('No cache available for client. Providing a cache interface can improve client response times.');
+            $token = $this->_cache->get('access_token');
+
+            if ($token) {
+                $this->_accessToken = $token;
+
+                return;
             }
+        } else {
+            $this->_logger?->notice('No cache available for client. Providing a cache interface can improve client response times.');
         }
 
-        if (empty($this->_accessToken)) {
-            $this->refreshToken();
-        }
-
+        $this->refreshToken();
     }
 
     private function refreshToken(): void
@@ -185,9 +186,9 @@ class ApiTransport implements TransportInterface
             $body = $result->getBody()->getContents();
             $data = json_decode($body, true, 512, JSON_THROW_ON_ERROR);
 
-            $this->_accessToken = $data->access_token;
+            $this->_accessToken = $data['access_token'];
 
-            $this->_cache?->set('access_token', $this->_accessToken, $data->expires_in);
+            $this->_cache?->set('access_token', $this->_accessToken, $data['expires_in']);
 
         } catch (\JsonException | ServerException | RequestException | GuzzleException $exception) {