New-AzTemplateSpec PowerShell cmdlet

Module: Az.Resources

Creates a new Template Spec version with the specified ARM Template content. The content can either come from a raw JSON string (using FromJsonStringParameterSet parameter set) or from a specified JSON/Bicep file (using FromJsonFileParameterSet parameter set).

The following example creates a new Template Spec version "v1.0" in a Template Spec named "myTemplateSpec". The specified version will have $templateJson as the version's ARM Template content.

$templateJson = @"
{
    "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {},
  "resources": []
}
"@
New-AzTemplateSpec -ResourceGroupName 'myRG' -Name 'myTemplateSpec' -Version 'v1.0' -Location 'West US' -TemplateJson $templateJson

Additional details at New-AzTemplateSpec (Az.Resources) | Microsoft Docs