PAYWALL CONTENT - JSON LD MARKUP in AMP-ACCESS

Question

I have a question about AMP-ACCESS and ContentPaywall.

There is no example of how to do the JSON LD MARKUP in AMP for the contents with AMP-ACCESS, as if there is one for AMP SUBSCRIPTION where it indicates that you should include:

    "isPartOf": {
          "@type": ["CreativeWork", "Product"],
          "name": "The Norcal Tribune",
          **"productID": "norcal_tribune.com:basic"**
             }

Does AMP-ACCESS not need to include this in AMP microformats? Is no ProductID necessary?