The 4.11.4 Version Change Log shows
+ Add-ons: SEO: JSON-LD markup was added for products.
How do you add the fields to the products that the Google Structured Data system is actively looking for in products?
The google testing tool is posted at:
https://search.google.com/structured-data/testing-tool
If you input any product page on the testing tool it will show the missing fields that Google prefers to have for products.
Thank you in advance!
It depends on each one so you need to be more specific. You most likely will not be able to satisfy all of them either due to the addon not being capable or you simply do not use all of them.
You need specific schema structure codes that you have to place in the header section of your website. Then you test your URL in the testing tool after. You can search product schema generator on google where you will find easy and useful tools to generate schema. If you are using WordPress i suggest you to use insert header and footer plugin for placing schema codes.
I hope you got my point. If you want to know understand anything else let me know,