This is possible via custom CSS. If you add the below code in Custom HTML section in Landing page you can change the URL in <a href> Tag and the icon using Font Awesome 5 icons as shown below

<div class="landing-category-section">

<div class="category-title">

<h2>EXPLORE OUR KNOWLEDGE BASE</h2>

</div>

<div class="col-block center">

<a href="/v1.0/docs/">

<span class="category-icon fa fa-user-o " style="color:#068bc6">

</span>

<h3>Users and teams</h3>

<p>Define the access rights for your employees and vendors</p>

<span class="more-icon">

<i class="fa fa-arrow-circle-o-right"></i>

</span>

</a>

</div>

</div>