ethereal, 
Dilettante_Pro, или так... 
<div class="swiper-pagination swiper-pagination-fraction">
  <div>
    <span class="swiper-pagination-current">1</span>
    <span class="swiper-pagination-total">5</span>
    <span class="swiper-pagination-all">12</span>
  </div>
</div>
<script> 
	for(const element of document.querySelectorAll("span"))
		element.textContent = element.textContent.padStart(2, "0");
</script>