flask_ipam/app/templates/panel/_modal.html

<div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
        <div class="modal-header">
            <h5 class="modal-title text-{{modal.color}}">{{ modal.title }}</h5>
            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
        </div>
        <div class="modal-body">
            <p>{{ modal.body|safe }}</p>
        </div>  
        <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Close</button>
            {% if modal.action == 'delete' %}
            <a href="{{modal.action_url}}?page={{old_page}}" class="btn btn-{{modal.color}}">{{modal.action_text}}</a>
            {% else %}
            <button type="button" class="btn btn-primary">Save changes</button>
            {% endif %}
        </div>
    </div>
</div>