RemixIconEx.System.external_link

You're seeing just the function external_link, go back to RemixIconEx.System module for more information.
Link to this function

external_link(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.System.external_link()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M10 6v2H5v11h11v-5h2v6a1 1 0 0 1-1 1H4a1 1 0 0 1-1-1V7a1 1 0 0 1 1-1h6zm11-3v8h-2V6.413l-7.793 7.794-1.414-1.414L17.585 5H13V3h8z" />
</svg>

example usage

svg.icon {
  width: 96;
  height: 96;
}