What does this mean?
Meta tags are snippets of text that describe a page’s content in the page’s source code.
The meta tags don’t appear on the page itself, but they’re little content descriptors that tell search engines like Google what a web page is about.
Meta tags only exist in HTML, usually at the ‘head’ of the page, and so are only visible to search engines (and people who know where to look).
What to do?
You need to add meta tags. Learn how to do this, here: https://ahrefs.com/blog/seo-meta-tags/