JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js"></script>
<div class="container">
  <div class="row">

    <div class="col-12 center">
     <div class="card">
      <div class="card-body">
       This is some text within a card body.
      </div>
     </div>      
    </div>

  </div>
</div>

CSS

.center{
  display: flex;
  justify-content: center;
  align-items: center;
}