System Generated Notifications are notifications generated and sent by the system. You can either delete all the system notifications or manually check the notifications to delete.
If you want to delete all the system notifications then execute the query,
delete from notification where senderid=1;
To get the list of notification titles to delete unwanted notifications, execute the query,
select notificationtitle from notification limit 100;
Example: If the notificationtitle is ‘has been added to the group’, then use the query to delete notifications under this title,
delete from notification where notificationtitle like ‘%has been added to the group%’;