If you don't know How To Delete A Group On Facebook (https://allinsider.net/how-to-delete-a-facebook-group/) on a web browser then follow these steps:-
1. Log in to your Facebook account.
2. Click Groups from the left menu.
3. Select the group under Groups you manage.
4. Click People, then the three dots next to each member.
5. Click Ban from group and confirm for each member.
6. After removing all, click the three dots next to your name.
7. Click Leave group.
8. If prompted, assign a new admin or choose to delete.
9. Click Delete Group to confirm.