Rails StimulusJS cant close fullscreen

I have managed to get it working via Stimulus and going to full screen is working well but for the life of me I can't work out how to exit full screen by clicking the same icon. I hope someone can help, thanks

import { Controller } from "@hotwired/stimulus"

export default class extends Controller {
  static targets = ["fullScreen"]

  connect() {

  }


  openFullscreen() {
    if (!document.requestFullscreen) {
      this.fullScreenTarget.requestFullscreen()
    } else {
      this.fullScreenTarget.exitFullscreen()
    }
  }
}

EDIT

perfect I followed the docs and added this, and it works well, is this ok? Thanks

openFullscreen() {
        if (document.fullscreenElement) {
            document.exitFullscreen()
        } else {
            this.fullScreenTarget.requestFullscreen();
        }
    }
}