Apple App Store
Apple app reviews can be managed on the "Ratings and Reviews" page. You would need an "Admin" or "Customer Support" role to access this page and be able to view, sort, and respond to reviews.
More information about managing reviews and ratings here.
Google Play Store
Google app reviews can be managed on the "Reviews" page in the Google Play Console. To access this page, you need a user account with the "reply to reviews" permission enabled. More information on this can be found here.
Setting up email alerts for new reviews is possible within the Google Play Console. You can set up email alerts for reviews.
In conclusion, managing app reviews is important to maintaining a successful app. By regularly monitoring the reviews and feedback left by your users, you can make improvements and keep your users happy.