{% load bootstrap4 %}
<h4 class="sidebar-heading mt-4 px-3">Période</h4>
<form class="form px-3" action="" method="get">
  {% bootstrap_form form layout="inline" %}
  <input type="hidden" name="graph" value="{{active}}" />
  {% bootstrap_button "Ok" button_type="submit" button_class="btn btn-dark btn-block" %}
</form>