1. Did you check your spam folder? If your server is on a blacklist, or even if you do not have SPF or DKIM enabled on your mail server, the email can go to spam.
2. If you do not see the email, even in your spam folder, it is possible that your host is not configured to send email. The plugin uses wp_mail() to send the emails, and this requires some initial setup. My recommendation to you is to check with another plugin and see if emails are being sent. For example: https://wordpress.org/plugins/check-email/
3. Finally, check both the originating (admin) address and the receiving address to make sure there’s no errors.