Click the Timeoff link on the left-hand menu. There you see all of the requests for time off as well as their status (pending/approved).
You can use the filter icon to narraw the result, or show all the requests.
To created a new request, click the + in the top right corner. There a new panel appears on the right.
Select the days you want off by clicking on the calendar icon. Finally, click Submit to finish.
In order to view status or cancel requests, click on the request name (highlighted in orange). There a new panel appears on the right. At the bottom, you can chose to cancel the request, depending on the status of the request.