fixing widget builder link

docs/develop/asset-transfer-via-nitro/tools/nitro-widget/README.md

@@ -32,7 +32,7 @@ document.getElementById("widget__iframe").src = `${baseUrl}?${paramString}`;
 ```
 
 :::note
-1. You can use [Nitro's Widget Builder Tool](https://nitro.routerprotocol.com/widget) to automatically generate the widget paramaters.
+1. You can use [Nitro's Widget Builder Tool](https://app.routernitro.com/widget) to automatically generate the widget paramaters.
 2. In case you want source / destination token to be native token, then the following value should be used for token address - 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE
 3. To integrate the widget on your UI, you will be assigned a unique partner ID. To get your partner ID, please use the link [here](https://app.routernitro.com/partnerId).
 :::