Listen to on-chain events and trigger your function whenever these are emitted.
Interface:
engine.onEvent(
fn, // function to execute
contractAddress, // smart contract address
abi, // Application Binary Interface (ABI) for an Ethereum smart contract. (array)
eventNames, // array of the contract's event names you wish to listen to
network, // string representation of one of the supported networks
config // your custom configuration. key:value object
)
