diff --git a/includes/class-api.php b/includes/class-api.php
index c1a36f8..561af9c 100644
--- a/includes/class-api.php
+++ b/includes/class-api.php
@@ -22,11 +22,11 @@ class Api {
     private Issuu $client;
 
     public function __construct() {
-        if (!Settings::exists('token')) return;
-        $this->client = new Issuu(Settings::get('token'));
+        if (!Settings::exists('client_id')) return;
+        $this->client = new Issuu(Settings::get('client_id'));
     }
 
-    public function get_publications(array $args = []):stdClass {
+    public function get_publications(array $args = []):?stdClass {
         if (!isset($this->client)) return null;
 
         $args = wp_parse_args($args, [
@@ -45,7 +45,7 @@ class Api {
         }
     }
 
-    public function get_publication(string $slug):stdClass {
+    public function get_publication(string $slug):?stdClass {
         if (!isset($this->client)) return null;
 
         $publications = new Publications($this->client);
@@ -57,7 +57,7 @@ class Api {
         }
     }
 
-    public function get_publication_assets(string $slug, array $args = []):stdClass {
+    public function get_publication_assets(string $slug, array $args = []):?stdClass {
         if (!isset($this->client)) return null;
 
         $publications = new ApiPublications($this->client);
@@ -69,7 +69,7 @@ class Api {
         }
     }
 
-    public function get_publication_embed(string $slug, array $args = []):stdClass {
+    public function get_publication_embed(string $slug, array $args = []):?stdClass {
         if (!isset($this->client)) return null;
 
         $publications = new ApiPublications($this->client);