Use correct session storage item key

public/typo3conf/ext/ep_theme/Resources/Private/Assets/js/myep/Events.vue

@@ -88,7 +88,7 @@
                     + '/api/events/'
                     + event.id
                     + '/' + type + '?token='
-                    + sessionStorage.getItem('token');
+                    + sessionStorage.getItem('myep-auth-token');
             },
             calculateBalance (event) {
                 if (!event.price || !event.payment) {