How to use Bitcoind walletnotify in bitcoin.conf?

I want to use the walletnotify command and request my rest.l API from node.js but I have the exception

system (curl –url http://192.168.3.2:3000/api/btc/WalletNotify/c39177b52e49656ad54a1ee6291566da868926cdc0ca446f89bc79cf3447b326) returned 32512

I am using it; walletnotify = curl –url http://192.168.3.2:3000/api/btc/WalletNotify/%s

How can the walletnotify command be used?