Empty network configuration in Azure (networkconfig.xml)

I've recently created an Azure trial account, and we've got it set up and connected to our on-prem network (via IPSec tunnel over ASA). I can communicate with a Linux VM I threw up in Azure from my machine on premise. Now, I'd like to include a couple other sites outside of Azure as well. So essentially, I'd like one specific resource in Azure to connect to three different locations in the US.

According to the reading I've done, it seems I can't make three tunnels that point to the same virtual network (as virtual network gateways don't work like that). All the documentation points to downloading the network config and editing it (like here: https://docs.microsoft.com/en-gb/azure/vpn-gateway/vpn-gateway-multi-site) So I'm trying the ol' download the network configuration procedure. But, when I connect via the newest Azure CLI powershell and login to my account and run this command:

Get-AzureVNetConfig -ExportToFile

I get an empty file. So I ran

Get-AzureVNetConfig -verbose

And I get this as a response:

VERBOSE: 3:47:55 PM - Begin Operation: Get-AzureVNetConfig

Get-AzureVNetConfig : ResourceNotFound: Network configuration does not exist.

At line:1 char:1 + Get-AzureVNetConfig -Verbose + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : CloseError: (:) [Get-AzureVNetConfig], CloudExce ption + FullyQualifiedErrorId : Microsoft.WindowsAzure.Commands.ServiceManagemen t.IaaS.GetAzureVNetConfigCommand

I know I have a network- is this a limitation of having a trial account?

I hope I'm being clear here- please let me know if there's any information I should be adding that's not glaringly obvious to me. Thanks everyone.

edit to add: Here's what my VNetConfig looks like if I just run Get-AzureVNetConfig -ExportToFile C:\herbajerb.xml

<NetworkConfiguration

xmlns="http://schemas.microsoft.com/ServiceHosting/2011/07/NetworkConfiguration" >
<VirtualNetworkConfiguration />
</NetworkConfiguration>