How to fire event in integration test?

I'm trying fire even in my integration test but it does not triggering. I set up QUEUE_DRIVER=sync in my phpunit xml. Why event and listener is not working ? The workflow of my app is next:

Create some entity. Send it to remote server (i use even and listener); Give back some id and write it to db.

 public function testCanGetCbdOfPlan() {
        $plan = factory(Plan::class)->create();
        $plan->save();
        Event::fire(new PlanSaveEvent($plan));
//
        $this->assertNotEmpty($plan->cbd_id, 'CBD_ID is empty');
    }