For any scheduled online exams, the extra time will not show on your timetable however it will have been applied in the system (i.e. ExamSys or Moodle) and will be displayed when you log in on the day of your exam.
In-person exams will include your extra time on your exam timetable. If your extra time has not been added for your in-person exams, please contact the Exams Office here (select '01c. Exams' from the drop-down list).
Did you miss the deadline to have your accommodations put in place (deadline as published here)?
If exam accommodations are added to your Support Plan after the deadline, they are unlikely to be in place for ExamSys or written exams in that period, due to the complexity of scheduling across the university.
However, some adjustments may still be possible for Moodle-based assessments.