<svg class="e-bolt-icon">
is acceptable at rendering an icon, though the Twig template is the recommended usage for Drupal.
<svg>
HTML element, be sure to minifiy the SVG, add the element class class="e-bolt-icon"
, and add the attribute aria-hidden="true"
.{% include '@bolt-elements-icon/icon.twig' with {
name: 'bell-solid',
} only %}
<svg class="e-bolt-icon" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" aria-hidden="true">...</svg>