The quickest way to delete a collection is from the home page. Click on the vertical "..." icon that appears when you hover over the collection tile, then click "Delete".
Alternatively, you can open the collection settings by clicking on the collection title when it’s open then select "'Permanently delete Collection" from the actions menu.
Please note, deleting a collection is an irreversible action. Once you’ve deleted a collection, it cannot be recovered. Click "Delete" to confirm.
Only the collection owner will be able to delete a collection. To learn more about permissions, read the guide to user permissions.