Reviewers play a vital role in ensuring the quality of scholarly publishing.
When you register as a user with the website, you may be asked to sign up for the reviewer role. If this has been enabled, you can add the reviewer role at any time, even if you've already registered, by going to the User Profile page in the dashboard.
You'll also be asked to specify your reviewer interests, so that editors can make better choices when selecting reviewers for a submission.