To accept or decline a meeting request you should: 

1)Go to your Inbox

2) Click on Requests received.

3)Click on View request.

4) You will be able to see the recommended times and the button Decline request. If you want to have a meeting with the participant, you should choose one of the options and a notification will be sent to the counterpart. If not, you can press the button “decline request” and you won’t have a meeting scheduled with that counterpart.