api-contract documentation is very outdated. We are working on updating it as we speak.
createBlueprint is no longer available. You can use
CodePromise to upload and instantiate new code and
BlueprintPromise to instantiate code that is already on-chain.
The 2 classes respectively map to the
instantiate dispatchables in the Substrate FRAME contracts pallet
In both cases you would instantiate by calling
tx[constructorName] on the resulting object (code or blueprint) with the right arguments.
You can read more about the arguments in the metadata section
and also refer to the implementation in Polkadot.js Apps for Blueprint and Code.