Missing Structured Data
Criticalno-structured-data
What it checks
Page has no JSON-LD, Microdata, or RDFa structured data
How to fix it
Add JSON-LD structured data to help search engines understand your content. Start with Organization schema for your homepage, and Article/Product schemas for content pages.
More detail: https://developers.google.com/search/docs/appearance/structured-data/intro-structured-data.