{% load wagtailadmin_tags %}
{% if url %}
    <a class="button{% if classname %} {{ classname }}{% endif %}" href="{{ url }}">{% if icon_name %}{% icon name=icon_name %}{% endif %}{{ label }}</a>
{% else %}
    <button type="submit" name="{{ name }}" value="{{ label }}" class="button{% if classname %} {{ classname }}{% endif %}">{% if icon_name %}{% icon name=icon_name %}{% endif %}{{ label }}</button>
{% endif %}