To prevent that requests bypass the review step, you can designate a Default Reviewer. If no other Reviewer is specified based on the review and coding matrix, requests will automatically be assigned to this Default Reviewer.
To set a Default Reviewer, open the approval workflow. In the review step, click on the ADD A REVIEWER button underneath Default Reviewer:
Please note: The option Default Reviewer is only available if there are no Reviewers with the rule Always Reviews.