Hi guys
I want to know details about sendtoaddress method in bitcoin core. especially the usage of arguments like:

replaceable

conf_target

estimate_mode

if estimate_mode is unset, how fee calculated?

hi, i am an amateur in blockchain, So forgive me for the trivial questions

I want to know the difference between listreceivedbyaddress and listaddressgroupings method in the bitcoin-cli?

it is wired after call this: bitcoin-cli -regtest generatetoaddress 101 $(bitcoin-cli -regtest getnewaddress)

with listaddressgroupings i have 50 bitcoin, but with listreceivedbyaddress i have zero (by same address)

hi everyone
I want to use "sendtoaddress" method for withdrawing my users.

1) if I set "subtractfeefromamount" to false, fee deducted from where? and How is fee calculated?

2) for example , if i have 2 bitcoin in my wallet, and the user withdraws one bitcoin, the rest coin (one bitcoin - fee) how calculated (utxo) ?

3) consider the above example, I want the rest coin return to the new address (different from the source address (HD wallet)), Is there a way?

hi guys, I am a new developer in crypto. 

i installed bitcoind and bitcoin-cli, so create watch only wallet by the below command:
bitcoin-cli -testnet createwallet testwallet true
so my testwallet has no private key, then i expect generate a new HD address with this command:
bitcoin-cli -testnet -rpcwallet=testwallet getnewaddress
but got this error:
error code: -4
error message:
Error: This wallet has no available keys

please help me, i want create my cold wallet that has a lot of slot to receive money without private key.