Hello Vladimir,
Thanks for reaching out concerning your product pages. I assume you meant that the Yoast SEO metabox is not showing.
– Can you confirm you have the right user permissions? You can check by going to Users > Your Name > Yoast SEO settings (may need to scroll down) and confirm that both “Disable SEO analysis” and “Disable readability analysis” are unchecked?
– Can you confirm that SEO, Readability, and Insights are enabled by going to SEO > General > Features and checking that SEO, Readability, and Insights are enabled?
– Can you confirm that SEO and Readability are enabled on the product pages? You can check by going to SEO > Search Appearance > Content Types and seeing that the Yoast SEO Meta box says “Show”?
– Can you confirm that if you go to the page and click on Screen Options (in the top right), are all the right options enabled? If you are using the new Gutenberg editor, you will need to click on the dots in the corner and select options. See image: https://pasteboard.co/I0PzCxd.png, which highlights how to check this.
Do let us know how it goes.