Get Template Spec (with all versions) by name

Get information about the Template Spec named 'MyTemplateSpec' within the resource group 'myRG'.

Get-AzTemplateSpec -ResourceGroupName 'myRG' -Name 'MyTemplateSpec'

Note: All of the Template Spec's versions will be present within the ".Versions" property of the return object.

Get-AzTemplateSpec (Az.Resources) | Microsoft Docs