satchats on Nostr: What are alt npubs?

{ "id": "b74f861d8217dad4306608f7a3c2321e1965ea2010085df71cb4b581f973c030", "pubkey": "c7ec4b0353ccecc429b91645dff0c2c6cceaf468be8323c144ef5d403c928b6a", "created_at": 1760439153, "kind": 1, "tags": [ [ "p", "fc18abd568f73549cb01e3b6e2406f43ad7864cc59789dbd7cbfa8a6923f978c", "wss://relay.primal.net" ], [ "e", "8ec1653182a361af77527123423b88d15e616bba1054dc14240e74e91ac49192", "wss://relay.primal.net", "root", "fc18abd568f73549cb01e3b6e2406f43ad7864cc59789dbd7cbfa8a6923f978c" ] ], "content": "What are alt npubs? \n\n", "sig": "dd2abeeb19b87cbf5826157279e6b9524f80f16022a1e784d5a2ba30df9a88f7c6bb16c471afefc3fa78fcae526aa92f7d261c9876fbd99ae2ab0cea48514bed" }