Redirect Pro doesn't rely on traditional web crawlers like Google Search Console. Instead, it captures 404 errors as they occur during live customer sessions.
In other words, Redirect Pro only detects 404 broken links after they're visited.
This approach means that it make take some time to identify 404s when you first install the app, but it ensures that only relevant, customer-impacting broken links are flagged, allowing you to prioritise redirects that matter most.