Respondus Monitor is an add-on for Respondus LockDown Browser that requires students to use a webcam that will record them taking their quiz in BOLT.
The software actively checks for appropriate quizzing behavior and flags any unusual behavior for instructor's review.
When you are requiring LockDown Browser as in the article, How can I require LockDown Browser on a quiz?, at step 6, select "Require Respondus Monitor for this exam". Then click Save and Close.