nt: 'bottom-start',
    };
    if (contentFn) {
      config.content = contentFn;
    }
    if (onTriggerFn) {
      config.onTrigger = onTriggerFn;
    }
    if (onUntriggerFn) {
      config.onUntrigger = onUntriggerFn;
    }
    window.tippy(el, config); 
  }
  const noterefs = window.document.querySelectorAll('a[role="doc-noteref"]');
  for (var i=0; i<noterefs.length; i++) {
    const ref = noterefs[i];
    tippyHover(ref, function() {
      // use id or data attribute instead here
      let href = ref