dM on Nostr: Where is the key stored?

{ "id": "d43be7aaf7a81861a969339a09b6d81468f4a8cbbb3432e8b0fe1e967cf44084", "pubkey": "d011b40b1e3ec1daf73c8b4e5e8811ac624be9131241a11b536ad21ba9aca6a9", "created_at": 1691673792, "kind": 1, "tags": [ [ "p", "cf473ebe9736ba689c718de3d5ef38909bca57db3c38e3f9de7f5dadfc88ed6f", "" ], [ "p", "a9046cc9175dc5a45fb93a2c890f9a8b18c707fa6d695771aab9300081d3e21a", "wss://nostr.zbd.gg" ], [ "e", "0734d8b369b4e984f0e1dc65901ec7910020d9b027d539d16d10a0f395eb1fa1", "wss://relayable.org", "root" ], [ "e", "c1844da259b6f9cd08917fd6ab240176f9d526b70bd1e7bc457a1471e7aa5c7a", "wss://nostr.mom", "reply" ] ], "content": "Where is the key stored?", "sig": "c234b5de02aa68f6020c4b0cb69302fadaebb144374798cacd79801202a677b71a9b801a478ac2cff12610a205cf33002134ee1eb25a094d65846bdca0a17aa1" }