What does this mean?
We could not find a robots file for your site, but this is an important file for search engines.
Robots.txt is a text file webmasters create to instruct web robots (typically search engine robots) how to crawl pages on their website.
The robots.txt file is part of the robots' exclusion protocol (REP), a group of web standards that regulate how robots crawl the web, access and index content, and serve that content up to users.
What to do?
Get a robot file for your site or talk to your developer.
You can automatically fix this issue for WordPress websites, by clicking on the "Autofix" button
Learn more, here: https://www.seeme-media.com/robots-txt/