     th:placeholder="#{chaincode_callback_location_placeholder}"
                                                   th:field="*{callbackLocation}">
                                        </div>
                                        <div class="form-group" id="event_group" style="display: none">
                                            <label class="form-label" th:text="#{chaincode_events}"></label>
                                            <input type="text" class="form-control is-valid"
           