You use the Shared Code service to change the behavior of the close tab button.
Example of code added to the navigator-tabs component.
import { SharedCodeService } from 'services/shared-code'; import { GetInjectedContext } from '../../../inject-context'; const NavigatorTabs = props => { const MainComp = GetInjectedContext('Components.NavigatorTabs'); SharedCodeService().navigatorTabsRegularTabClose = ({ event, id, dispatch, actions, }) => { event.stopPropagation(); dispatch(actions.closeTab(id)); //call your code console.log(`Tab with ID: ${id} was closed.`); }; return <MainComp props={props}></MainComp>; }; export default NavigatorTabs;