RemixIconEx.System.arrow_up

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

arrow_up(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.System.arrow_up()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M13 7.828V20h-2V7.828l-5.364 5.364-1.414-1.414L12 4l7.778 7.778-1.414 1.414L13 7.828z" />
</svg>

example usage

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