I believe Cloud NGFW is available only with PAYG.
Please refer to 6th page of the datasheet.
https://www.paloaltonetworks.com/resources/datasheets/cloud-ngfw-for-azure
Simple Procurement and Setup With Cloud NGFW for Azure, you can implement next-generation network security in minutes. Procure Cloud NGFW via Azure Marketplace, set it up with a few clicks, and integrate with native Azure services, such as Azure Key Vault and Azure Virtual WAN. You can set up rulestacks and automated security profiles in only a few minutes.
Cloud NGFW for Azure is available as a pay-as-you-go service. You pay an hourly rate for each availability zone where your NGFW is deployed. You also pay for the amount of traffic, billed by the gigabyte, processed by the NGFW.
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