To disable notification dots,

1. Go to phone settings
2. Click on “Apps & notifications” or “Apps”
3. Find “Messages Pro” or “Advance SMS”
4. click no “Notifications” or “App notifications”
5. Find “Allow notification dots”
6. Disable it

Checkout blow link for more information. : https://www.howtogeek.com/324124/how-to-enable-or-disable-notification-dots-in-android-8.0-oreo/