... transform-runtime as a plugin, to include the Babel runtime. Otherwise, you'll receive an error. Options can be passed to Babel in a variety of ways. When passed directly to Babel, you can just pass the options object. When Babel is used via a wrapper, it may also be necessary, or at least more useful, to pass the options via configuration files. Babel is a toolchain that is mainly used to convert ECMAScript 2015+ code into a backward-compatible version of JavaScript in current environments.