It’s possible they don’t have the note to delete then. If they do, just add a nip-05 on the npub. Once you’re done deleting the notes, you can remove the nip-05 or just nuke the kind 0.
They probably don't have it, since I never had a NIP-05 on that npub and haven't used it in half a year.
Just thought it was interesting that not having a NIP-05 might prevent you from persistently deleting your own events.