After task done dust container not fully empty

The tas was done, there was a sound of dust bin emptying but after I opened the bin of the robot, some trash was still there. I did not find any button in the app to trigger the manual emptying. Can it be done?

Yes, there is a empty dustbin option when your robot is docked. it should be on the bottom right, take a screenshot if you can not find it and I can assist you further