Page not served over HTTPS
What this means
The URL is plain HTTP. Browsers mark such pages "Not Secure", and HTTPS has been a confirmed ranking signal since 2014.
How to fix it
Install a TLS certificate, serve everything over HTTPS, and 301-redirect the HTTP URLs to their HTTPS equivalents.
Fix effort
This check needs a developer fix: it turns on a routing, hosting or infrastructure decision that no automatic edit can make safely.
Authoritative source
https://developers.google.com/search/docs/crawling-indexing/site-move-with-url-changes
Find every page this affects
CrawlX runs this check — and 161 others — across your whole site, ranks the findings by estimated impact, and opens the fixable ones as pull requests. Free for 500 URLs.