Hello @vamsi krishna
Using command az webapp show --resource-group <group_name> --name <app_name> --query outboundIpAddresses --output tsv
you will only see the list of WebApp global outbound Ip addresses.
When you are connecting WebApp to VNET, VNET traffic is already NATed with last IP address from the subnet range.
For example WebApp is connected to VNET with subnet 10.0.0.0/24, so IP address of your WebApp will be 10.0.0.253
You can check WebApp outbound IP by making a request to WebApp in browser and see IP address of the response in Browser Console