Individuals with read-write access can add ad hoc approvers or watchers. Follow the steps in the Add an Ad Hoc Reviewer user guide article.
For IACUC, once your sponsor has indicated that you are likely to be funded for your grant application (that you have a fundable score) you will need to have the Institutional Animal Care and Use Committee (IACUC) review your eGC1. Your application will be in Approved status at this time, so you will add them as a Watcher. This will send an email to the committee alerting them that their review is needed.