if your nostr client doesn't support deletes, you can use this web application to delete your content: https://nostr-delete.vercel.app

you'll need to have a nostr web browser extension installed to proceed. i like Alby or Nostr Connect.

there are two caveats with this tool.

1) this will only work for relays that support NIP-09 deletes. *most* relays do support deletion, but some may not.

2) caching services or applications that use them may hold onto your content until that cache expires.