Fix path

src/db.ts

@@ -15,7 +15,7 @@ class DBService {
   private constructor() {
     this.dataSource = new DataSource({
       type: "sqlite",
-      database: "data/push_server",
+      database: "/usr/src/app/data/push_server",  
       entities: [VapidKeys, Subscription],
       synchronize: true
     });