brotli cannot be used with static sources such as CSS, JS, images, .... Brotli content encoding only works with dynamically generated sources such as the main document. So that brotli can be used at all, the corresponding function must be activated in the LiteSpeed webserver configuration. But if you use ESI, then brotli cannot be used in this case either. You should therefore first contact your hosting provider to see whether he has activated brotli.
btw. the port used doesn't matter for brotli