I have created an alert rule and associated it with a VM. Now trying to fetch the alert rule through Powershell, but getting null. What's wrong with this code ?

Get-AzAlertRule -ResourceGroupName 'pacbldnew'

[see the alert rule](https://i.stack.imgur.com/YY3A5.png)
[powershell code returning null](https://i.stack.imgur.com/YL0B5.png)