If your application can switch between Mainnet and Testnet networks you may want to add the network selector widget to the CSPR.click navigation bar.
## Network selector set up
Define an array with the list of networks your application supports:
```javascript
const NETWORKS = ['Mainnet', 'Testnet'];
const networkSettings = {
networks: NETWORKS,
currentNetwork: NETWORKS[0],
onNetworkSwitch: (n) => {
console.log('Network selected', n);
window.csprclickUI.setNetwork(n);
},
}
```
Then, add this settings object to the UI initialization defined before:
```javascript
const clickUIOptions = {
uiContainer: 'csprclick-ui',
rootAppElement: '#app',
showTopBar: true,
networkSettings,
};
```
### Customize the network icons
You can also specify your custom icons for each of the networks:
```tsx
import mainnetIcon from './assets/ico-mainnet.svg'
import testnetIcon from './assets/ico-testnet.svg'
const NETWORKS = [
{ title: 'Mainnet', icon: mainnetIcon },
{ title: 'Testnet', icon: testnetIcon }
];
```
---
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