robots.txt is an HTML page
robots.invalid
What it means
The robots.txt address returns HTML (often a 404 page served with status 200), so crawlers cannot read any rules.
Priority
P2
How to fix it
Run a free check of your page. The report shows the evidence for this finding on your site and a ready-to-paste fix: a robots.txt change, a Cloudflare rule, JSON-LD markup, an llms.txt draft or a short instruction.
How to confirm the fix
After the change, press "Check again" on the report: it lists what was fixed and how the score changed.