To use test case review system for your project, go to "Settings" menu and select "General".

On general settings page you would get 2 options:

In order to enable the test cases review system, use the toggle button provided. This will provide an option to users adding a new test case or editing existing ones to get their work approved by a reviewer. But it would not be mandatory for them to get test cases approved after every add or edit operation.

Once the review system is enabled, you would notice that the second checkbox that makes approval mandatory would be made available for selection, i.e. with this you can set whether all the add and edit operations on test case would need to be approved by a reviewer or not.

When approval is made mandatory, you would be required to select the user who will be the primary reviewer for test cases in project. This means whenever there is an operation (like bulk update, bulk copy, copy and revert) where user performing the operation cannot specify the reviewer for test cases being affected then the user selected here will be considered as the default reviewer.

Optionally you can also select a secondary reviewer, the user who will be considered as reviewer if the above mentioned operations are being performed by primary reviewer.

You can see the key difference while adding a new test case:

Approval is mandatory

Here you can see that selection of a Reviewer is mandatory.

Approval is optional

Note that the Reviewer field is available on add test case form but user has option to not to send the test case for approval.

Based on whether you want a review system to be available for the current project and how the approval process would work, these options can be set.

Note: