Electrum wallet requires a special Electrum compatible server where it can query the data needed.
There are now several implementations eg:
...code snippet that implements such funtionality
Descriptors in Bitcoin Core can have a suffixed checksum.
You pass the checksum 3qpdv9la. ...
Is it true, that Bitcoin somehow synchronize old wallet with the current state of the network
Yes. If the wallet file is not synced with the current blockchain state, a rescan will occur starting from the block that is recorded in the wallet file. It does not rescan all of history, only the things that it has not yet seen.
and that's why it takes so much ...
It's not working because it does not have sufficient data to give you a reasonable estimation.
You will need a steady rate of transactions on the network for a sustained period of time. On regtest, that means you'll need to simulate those transactions as there is no network to provide them.
It's easier to see estimatesmartfee in action on testnet or ...
You may be trying to validate a mainnet address on a testnet/regtest client.
For the benefit of others:
$command = new \Nbobtc\Command\Command('getinfo');
$client = new \Nbobtc\Http\Client('http://username:password@localhost:18332');
# legacy testnet address
#$address = "mvM368BXwRNx4HcYdL8XbU8hAX274gMKcq";
Yes that possible:
you need to know the txid and Vout index for those particular addresses when they were funded
for example here i have used 3 addressees to send some BTC to single addresses 2N6V6Ko17CPWaZZf6YrGKeq8R1fzbqrTKLF and if know the txid and vout of those addresses when they were funded i will do:
1)create raw tranaction