Follow the below instructions to Notify/Nudge Managers to complete Employee Evaluations.
Step 1: Performance > Manage Reviews > Select Cycle > Actions

Step 2: Reviewer > Nudge employee with pending Manager review Submissions > Done

Step 3: Select users either Individually or in Bulk > Click on Notify.

Step 4: Edit the Subject & Message if required and click on Notify

This will send an email as well as an In-App notification for the Managers to complete their Employee Evaluations.