The dashboard shows you your total time off taken/pending/approved.
Click Dashboard > My info > Request Time off / Leave
Then click Add Vacation Lieu time, or Absence
Then choose what type of time off you are requesting.
Select the days/hours you wish to request, afterwards your manager will receive the request and will approve or reject as appropriate.
Note: If your organization has not enabled Lieu time, the button may read "Add Vacation or Absence"