1) Disable BigCommerce Reviews Widget

Go to Advanced Settings > Comments and select Built-in tab.

screenshot-store-2021.10.27-08_55_10.png

 

De-select product reviews and save changes.

 

2) Disable BigCommerce Review Request Emails

Go to Store Setup > Store Settings and select Miscellaneous tab.

screenshot-store-2021.10.27-08_57_36.png

 

De-select Product Review Emails and save changes.