Reports whether IndexNow is set up for a property: whether an API key is configured (masked to its last four characters, the full key is never returned) AND whether the key file is actually reachable on the site. Both are required before search engines accept submissions. When keyFileVerified is false, keyFileUrl is the exact file the site owner must publish, containing the key and nothing else. keyFileVerified is null when the check was inconclusive (timeout or a bot rule), which is not a failure. Check here before submit_indexnow_urls and whenever a submission fails. When no key is set, call update_indexnow_settings with generateKey: true and publish the key file it returns.