{% if referrer is none %}
	<button type="submit" class="btn btn-outline-dark m-2" disabled>Go back <i class="fa fa-arrow-left"></i></button>
{% else %}
	<a href="{{ referrer }}"><button type="submit" class="btn btn-outline-dark m-2">Go back <i class="fa fa-arrow-left"></i></button></a>
{% endif %}