JSFiddle - React, Tailwind, and code Playground

HTML

<div id="donation_element1_row">Block</div>
<div id="donation_element2_row">Block</div>
<div id="donation_element3_row">Block</div>
<div id="donation_element4_row">Block</div>
<div id="donation_element5_row">Block</div>

<div id="addDiv">+ Add Block</div>

CSS

div[id*='donation_element']{
  background-color: blue;
  display: none;
}

div#donation_element1_row {
  display: block;
}

#addDiv {
  background-color: grey;
}

#addDiv, div[id*='donation_element']{
   padding: 20px 30px;
   color: #fff;
   margin: 10px;
 }

JavaScript

var count = 0,
    $allDivs = $(' #donation_element2_row, #donation_element3_row, #donation_element4_row, #donation_element5_row');

$('div#addDiv').click( function() {
    if( count < $allDivs.length  ) {
        $allDivs.eq( count ).show( 'slow' );
        count++;
    }
});