murph-skeleton/core/Resources/views/task/task_admin/run.html.twig

<div class="modal-dialog">
    <div class="modal-content">
        <div class="modal-header">
            <h5 class="modal-title">
                {{ 'Results'|trans }}
            </h5>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                <span aria-hidden="true">&times;</span>
            </button>
        </div>
        <div class="modal-body">
            <pre>{{ output|trim }}</pre>
        </div>
        <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-dismiss="modal">{{ 'Close'|trans }}</button>
        </div>
    </div>
</div>