JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block" style="height:200px;">Block 1</div>
<div class="block" style="height:200px;">Block 2</div>
<div class="block" style="height:200px;display: none;">Block 3</div>
<div class="block" style="height:200px;display: none;">Block 4</div>

<a id="link" href="javascript:showblock();">Показать</a> 

<script>
var blki=2;
var elements = document.querySelectorAll('.block');

function showblock() {
    elements[blki].style.display = 'block';
    blki++;
    if(blki == elements.length){
        document.getElementById('link').style.display = 'none'; 
    }
}
</script>