healthchecks/templates/integrations/trello_settings.html

<p class="text-success">Authentication successful!</p>
<p>Please select the Trello list to post notifications to:</p>

<form method="post" class="form-horizontal">
    {% csrf_token %}
    <input type="hidden" id="settings" name="settings" data-token="{{ token }}"/>

    <div class="form-group {{ form.value.css_classes }}">
        <label for="list-selector" class="col-sm-3 control-label">Post Notifications to</label>
        <div class="col-sm-3">
            <select id="list-selector" name="board_list_id" class="form-control">
            {% for board in data %}
                <optgroup label="{{ board.name }}">
                    {% for list in board.lists %}
                        <option
                            data-list-id="{{ list.id }}"
                            data-board-name="{{ board.name }}"
                            data-list-name="{{ list.name}}"
                            value="{{ board.id }},{{ list.id}}">{{ list.name }}</option>
                    {% endfor %}
                </optgroup>
            {% endfor %}
            </select>

            {% if form.board_list_id.errors %}
            <div class="help-block">
                {{ form.board_list_id.errors|join:"" }}
            </div>
            {% endif %}
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-3 col-sm-9">
            <button type="submit" class="btn btn-primary">Save Integration</button>
        </div>
    </div>
</form>