Use the included .figure, .figure-img and .figure-caption classes to provide some baseline styles for the HTML5 <figure> and <figcaption> elements. Images in figures have no explicit size, so be sure to add the .img-fluid class to your <img> to make it responsive.

A caption for the above image.
<figure class="figure">
    <svg class="bd-placeholder-img figure-img img-fluid rounded" width="400" height="300" xmlns="" role="img" aria-label="Placeholder: 400x300" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="#868e96"></rect><text x="50%" y="50%" fill="#dee2e6" dy=".3em">400x300</text></svg>
    <figcaption class="figure-caption">A caption for the above image.</figcaption>