use the new session management

src/services/system.ts

@@ -1,9 +1,10 @@
 import axios from 'axios';
 import { Configuration } from './configuration';
+import { Session } from './session';
 
 export class System {
   static async timestamp(): Promise<number> {
-    const token = sessionStorage.getItem('token');
+    const token = Session.bearerToken();
     if (!token) return 0;
 
     return axios