<font-awesome-icon icon="fa-light fa-0" />
<FontAwesomeIcon icon="fa-light fa-0" />
.my-icon::before {
font: var(--fa-font-light);
content: "\30";
}
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512" style="width: 30px;height: 30px;fill: black">
<path d="M160 32.01c-88.22 0-160 71.78-160 160v127.1c0 88.22 71.78 160 160 160s160-71.78 160-160V192C320 103.8 248.2 32.01 160 32.01zM288 320c0 70.59-57.41 128-128 128s-128-57.41-128-128V192c0-70.59 57.41-128 128-128s128 57.41 128 128V320z"/>
</svg>
<i class="fa-light fa-0"></i>