This option is only available for those users with permission granted to create/edit assets.
If you want to delete an asset, select the asset you want to duplicate, open the contextual menu by clicking on the three points, and select the “Delete” option:
A popup message will appear, asking for the user’s confirmation:
By clicking “Cancel”, the system won’t delete the asset.
By clicking “Ok”, the system will delete the asset and all its children.
After the deletion, the asset tree will reflect the changes done: