I could be wrong but I doubt this is possible. I just refreshed myself on nostr.how “In order to interact with the Nostr protocol you must create a cryptographic signature each time you perform an action. Think of this signature as an authentication step where you confirm that you are, indeed, who you say you are.” Theoretically I imagine there could be some software similar to a signing extension that would middle-man the relationship and obscure/encrypt your nsec from them.

Maybe one day! Otherwise organizational accounts are in a bit of a sticky situation