JSFiddle - React, Tailwind, and code Playground

HTML

<li class="icono-cuadrado"></li>

CSS

.icono-cuadrado{
    width: 24px;
    height:24px;
    background-image: 
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24'><path d='M15,15.5A2.5,11.61 12,10.87 12,10C12,8.9 13,8 14.25,8C15.5,8 16.5,8.9 16.5,10C16.5,10.87 15.87Z' /></svg>");
}