[Doc]: New-AzApplicationGatewayBackendAddressPool - How use 'IP configuration ID' appears to be missing

### Type of issue

Missing information

### Feedback

New-AzApplicationGatewayBackendAddressPool
-Name
[-BackendIPAddresses ]
[-BackendFqdns ]
[-DefaultProfile ]
[-WhatIf]
[-Confirm]
[]

Description
The New-AzApplicationGatewayBackendAddressPool cmdlet creates a back-end address pool for an Azure application gateway. A back-end address can be specified as an IP address, a fully-qualified domain name (FQDN) or an IP configuration ID.

---

We have BackendAddressPools defined in production that include .BackendIpConfigurationsText that detail a VM's IP configuration ID.

How do we use New-AzApplicationGatewayBackendAddressPool to reference the VM's NetworkInterfaceIPConfig ID? The option appears to be missing from the cmtlet, New-AzApplicationGatewayBackendAddressPool, and no examples are provided.

(Get-AzNetworkInterfaceIpConfig -NetworkInterface (Get-AzNetworkInterface -ResourceId (Get-AzVm -Name 'myvm').NetworkProfile.NetworkInterfaces.Id)).Id

Thank you.

### Page URL

https://learn.microsoft.com/en-us/powershell/module/az.network/new-azapplicationgatewaybackendaddresspool?view=azps-13.1.0

### Content source URL

https://github.com/Azure/azure-powershell/blob/main/src/Network/Network/help/New-AzApplicationGatewayBackendAddressPool.md

### Author

_No response_

### Document Id

_No response_

Start with src/Network/Network/help/New-AzApplicationGatewayBackendAddressPool.md and compare its syntax and description with the reported BackendIpConfigurationsText behavior. Verify whether the cmdlet documents a supported IP configuration ID reference or lacks one; done means the page clearly explains the supported usage, limitation, or example.

Written by the indexing model from the issue text.