This might be simple question but I would highly appreciate if anyone can bring their wisdom on this.
If you install bitcoin-core software through https://bitcoincore.org/, it gives you dmg file that automatically install the bitcoin core (bitcoin-qt). I was assuming that you can still use JSON-RPC-API just with bitcoin-qt since it still communicates with the network and the GUI and RPC console. However, even when I enabled RPC server, when I use curl command which is specified on this wiki page: https://en.bitcoin.it/wiki/API_reference_(JSON-RPC), it doesn't return any result.
Does anyone know if it is still possible to use JSON-RPC API with just bitcoin-qt installed? If not, is there a way to install bitcoind/bitcoin-cli without going through IBD since bitcoin core already has all the blocks installed? It seems like unnecessary to redownload all the blocks while they are stored locally. If this is possible, how can I achieve this? Ideally, I think I should be able to use JSON-RPC-API just by installing bitcoin-qt from bitcoincore.org.