'Url' from 'webview' in react native

I want to know the URL every time it changes in Webview. I searched online a lot. And according to that, I have done these changes. But it is still not working.

What am I doing wrong here. Why its not working.

It only logs for the first time. or it works when I click some other button on the screen. What am I missing?

    import React, { Component } from 'react';
    import { Text, View, StyleSheet } from 'react-native';
    import { WebView } from 'react-native-webview';
    
    const initialUrl = 'https://www.youtube.com/';
    let url = '';
    
    class App extends Component {
    
      state = {
        url: initialUrl,
      };
    
      onNavigationStateChange = navState => {
        console.log("navstate=== ",navState)
        if (url!==navState.url) { 
          url = navState.url;
          alert(url);
          this.setState({
            url: url
          })
        }
      };
    
      render() {
        const { url } = this.state;
        const injectedJs = `
          var linkElements = document.getElementsByTagName("a");
            
          linkElements[0].addEventListener("click", function() {
            window.postMessage("addAccountSuccess?token=abc1234");
          });
          
          linkElements[1].addEventListener("click", function() {
            window.postMessage("addAccountError");
        `;
        return (
          <View style={{paddingTop: 24, flex: 1}}>
            <Text style={{backgroundColor: 'black', color: 'white'}}>{ url }</Text>
            <WebView
              style={{ flex: 1}}
              source={{
                uri: initialUrl,
              }}
              injectedJavaScript={injectedJs}
              startInLoadingState
              scalesPageToFit
              javaScriptEnabledAndroid={true}
              javaScriptEnabled={true}
              domStorageEnabled
              startInLoadingState={false}
              onNavigationStateChange={this.onNavigationStateChange.bind(this)}
              onMessage={event => {
                alert('MESSAGE >>>>' + event.nativeEvent.data);
              }}
              onLoadStart={() => {
                console.log("LOAD START ");
              }}
              onLoadEnd={() => {
                console.log('LOAD END');
              }}
              onError={err => {
                console.log('ERROR ');
                console.log(err);
              }}
            />
          </View>
        );
      }
    }
    
    export default App;