JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box-option option-title">
   <span>Title 1</span>
</div>
<div class="box-option option-title">
   <span>Title 2</span>
</div>
<div class="box-option option-title">
   <span>Title 3</span>
</div>
<div class="box-option option-title">
   <span>Title 4</span>
</div>

JavaScript

var groupOptions = document.getElementsByClassName("option-title");
for(var i = 0; i < groupOptions.length; i++){
    groupOptions[i].dataset.indice = (i + 1);
    groupOptions[i].addEventListener("click", message);
}

function message(){
    alert(this.dataset.indice);
}