I’m using bitcoin core full node on ubuntu. When I call listtransactions some transactions coming up with no fee key.

  [8] => Array     (         [account] =>          [address] => 1MTLEprpnQwLHMeYh51CQrCWxSuZPGSZ6T         [category] => send         [amount] => -0.0028107         [vout] => 0         [fee] => -1.13E-5         [confirmations] => 0         [trusted] => 1         [txid] => 6c74d8ac3b9b57184ed5dff72d48474c5ecf8dac4ec9388cb0ff33bf8e3bfcbc         [walletconflicts] => Array             (             )          [time] => 1511008107         [timereceived] => 1511008107         [bip125-replaceable] => no         [abandoned] =>      )  [9] => Array     (         [account] =>          [address] => 12zJ7ZbDW59mmNBPrxBAEjtWf8JzwgLNum         [category] => receive         [amount] => 0.00240164         [label] =>          [vout] => 0         [confirmations] => 0         [trusted] =>          [txid] => 25d0812c7dcf3c938430dc5c61566b8346b6e6d300b1e3cd3fc7d4031eb93cbe         [walletconflicts] => Array             (             )          [time] => 1511010977         [timereceived] => 1511010977         [bip125-replaceable] => no     ) 

)

Transaction on blockchain: https://blockchain.info/tx/25d0812c7dcf3c938430dc5c61566b8346b6e6d300b1e3cd3fc7d4031eb93cbe