Litecoin Core Wallet - null error during extracting private key

[Johnc10v10]

Dear sir

Kindly assist how to get litecoin core wallet private key.
Under Debug Window and Console,  i key in walletpassphrase passphrase 660, but i get 'null'  error message.

Thank you in advance

[MadGamer]

If you don't have a password in your wallet, that command is useless so proceed directly to this one: dumpprivkey "your address here" and If your wallet is encrypted, make sure you replace passphrase with your actual password If you haven't done so.