So the masterAccount parameter has this description within the docs
--masterAccount Account used to create requested account. [string] [required]
I have a few questions here:
1) If I need an account, to create an account, how am I supposed to make the original account?
2) It does not ask for the master account private key to sign the transaction, if the goal is that the master account "pays" for the creation of the specified account, then where do I sign the transaction with my private key? Perhaps I'm not far enough in the process but from the parameters I see no place to specify the publicKey
to sign
1) You can create original account in the web wallet for necessary network, e.g. https://wallet.testnet.nearprotocol.com/
2) The private key to sign transaction is taken from a key file for given account. It's inside network's subfolder of ./neardev/
folder currently used for key storage.
For example neardev/shared-test/generate-key-test.json
contains key for generate-key-test
account on shared-test
network.