checkForAutoPlay() {
    // select track to automatically play; prefer autoplayCaptionLanguage to default
    const
      readySubtitles = this.getSubtitles().filter(({isError}) => !isError),
      autoplayTrack =
        readySubtitles.find(({srclang}) => this.options.autoplayCaptionLanguage === srclang) ||
        readySubtitles.find(({isDefault}) => isDefault);

    if (autoplayTrack) {
      if (this.options.toggleCaptionsButtonWhenOnlyOne && readySubtitles.length === 1 && this.captionsButton) {
        this.captionsButton.dispatchEvent(createEvent('click', this.captionsButton));
      } else {
        const target = document.getElementById(`${autoplayTrack.trackId}-btn`)
        if (target) {
          target.checked = true;
          target.dispatchEvent(createEvent('click', target));
        }
      }
    }
  }
Check if we need to start playing any subtitle track.