BackHandler 或 webview 返回和退出应用程序

如何解决BackHandler 或 webview 返回和退出应用程序

我正在创建一个 webview，当单击 backHandler 时返回上一页，但我希望当您处于初始状态并单击返回关闭应用程序时，有人可以帮助我！！！

  const [canGoBack,setCanGoBack] = useState(false)
  const [currentUrl,setCurrentUrl] = useState('')
  const webviewRef = useRef(null)

   useEffect(() => {
 
    const backAction = () => { 
      if(webviewRef.current) webviewRef.current.goBack()
      return true;
    };
    
    const backHandler = BackHandler.addEventListener(
      "hardwareBackPress",backAction,);   

    return () => {
      backHandler.remove();
    };
  },[]);

 < WebView 
      
        onLoadStart={() => (showSpinner())}
        onLoadEnd={() => hideSpinner()}
        source = { {  uri : 'https://treinamento.viashopmoda.com.br/?origem=app'  } } 
        ref={webviewRef}
        onNavigationStateChange={navstate => {
          setCanGoBack(navstate.canGoBack)
          setCurrentUrl(navstate.url)
         
        }}
        renderError={() => 
        <View style={styles.loadingOrErrorView}>
        <View style={styles.container}>
        <Text style={{fontSize:25,marginBottom:25,color:'#BEBEBE',textAlign:'center'}}>Não foi possível conectar-se a internet</Text>
        <TouchableOpacity style={styles.botao} onPress={()=>recarregar()}>
          <Text style={{color:'#BEBEBE',fontSize:18,textAlign:'center'}}>Repetir</Text>
        </TouchableOpacity>
      </View>
      </View>    
      }
      />