How much JavaScript knowledge is required for using Stimulus?

How much JavaScript knowledge is required to use Stimulus effectively, ES3, ES5, ES6 or beyond?

Also interested, since it seems to be heavily relying on ES modules and ES6+

Much much less if it would be react or vue. The main feature I like it for what is that it’s highly structured unlike for example from jquery.

however, can reliance on modules and es6+ be ommited entirely?