Screen Saver Appcommon API doesnt work

I tried to get screen saver comes after some idle times. I have follow the guide on screen saver in webapis.appcommon but it still doesnt work. tested on tizen 5.5 and 6.5.

My code sample as follow:

          () => { console.log('success');},
          () => { console.log('error');}

I got success function callback but screen saver doesnt come out. Anybody knows any solution?