# **🔍 Overview**

When activating **Bing IndexNow** through OTTO on a WordPress site, some customers encounter an **"Index Now key not found"** error (HTTP 400). This happens even when the Search Atlas WordPress plugin is correctly installed and a CMS Connector connection is active. This article explains why the error occurs and how to resolve it.

# **⚠️ Why This Error Happens**

Bing's IndexNow verification process requires your site to serve a plain-text key file at a specific URL. The error is triggered when Bing cannot access that file. Common causes include:

- Your server uses **nginx** and returns a **403 Forbidden** response for `.txt` files in the site root.
- A **server-level rule** blocks direct access to root-level text files.
- A **caching layer or CDN** intercepts the request before the key file can be served.
- The key file was not yet written to disk at the moment Bing attempted verification.
- A previous plugin version did not include the virtual serving or `keyLocation` fallback logic now required for certain hosting environments.

# **✅ Step-by-Step Fix**

1. **Update the Search Atlas WordPress plugin.** Go to your WordPress dashboard, navigate to **Plugins → Installed Plugins**, and check for an available update to the Search Atlas plugin. Install the latest version — it includes a fix that serves the IndexNow key file virtually and adds a `keyLocation` fallback for nginx hosts that previously returned 403 errors.
2. **Verify the key file is accessible.** After updating, open a browser and go to `https://yourdomain.com/<your-indexnow-key>.txt`. Replace `<your-indexnow-key>` with the actual key shown in OTTO. The page should return a plain-text response containing only the key string. If you see a 403 or 404, proceed to the next steps.
3. **Check nginx or .htaccess rules.** If your host uses **nginx**, ask your hosting provider to confirm that `.txt` files in the web root are not blocked. If your host uses **Apache**, open your `.htaccess` file and look for any `Deny` or `FilesMatch` rules that may block `.txt` access.
4. **Purge your cache.** If you use a caching plugin (WP Rocket, W3 Total Cache, LiteSpeed Cache, etc.) or a CDN (Cloudflare, etc.), purge all cached files. Cached 404 or 403 responses can prevent Bing from seeing the key file even after the plugin is updated.
5. **Retry activation in OTTO.** In the Search Atlas platform, go to **OTTO SEO** (left sidebar) and open your site's OTTO dashboard. Navigate to **Indexing → Bing IndexNow** and click **Activate** (or **Retry**) to trigger a fresh key verification.

# **🔎 Confirm the Fix Worked**

After retrying activation, OTTO will show a **green active status** next to Bing IndexNow when verification succeeds. If the status remains red or the error persists, use the troubleshooting checklist below before contacting support.

# **📋 Troubleshooting Checklist**

- Plugin is updated to the latest Search Atlas version.
- Key file URL returns HTTP 200 with plain-text key content in a browser.
- No nginx `location` block or `.htaccess` rule blocks root `.txt` files.
- Site cache and CDN cache have been fully purged.
- WordPress site is publicly accessible (not behind basic auth or maintenance mode).
- OTTO activation was retried **after** completing all steps above.

# **💬 Still Seeing the Error?**

If you have completed every step above and the **"Index Now key not found"** error still appears, our team can investigate your specific server configuration. If you need further assistance, open the chat widget in the bottom-right corner of the platform and type **human teammate** to be connected with a member of our team.