You can find out if your test or quiz requires the LockDown Browser either by a notice from your instructor or if Requires Respondus LockDown Browser is included in the title of the assessment.
Select Tests & Quizzes.
In your Sakai course, select the Tests & Quizzes tool.
Review assessment title.
Assessments with Requires Respondus LockDown Browser appended to the title will require you to use the LockDown Browser to start and submit them.