Hi there! I understand you're having trouble finding or using the True Key browser extension. To help you better, could you please tell me which browser you're using? Also, is the extension missing completely, or is it installed but not functioning as expected?

Meanwhile, here are some general steps that often help resolve True Key extension issues on Windows 10:

1. Check Browser Compatibility: True Key extensions may not be supported on all browsers or all browser versions. For example, the extension might not be available or officially supported on older or less common browsers.

2. Install or Reinstall the Extension:
- For Chrome, you can get the True Key extension from the Chrome Web Store. If it's installed, try removing it and reinstalling the latest version.
- For Firefox, sometimes the extension isn’t available in the official add-ons store. In such cases, manual installation using an XPI file might be required.

3. Clear Browser Cache and Cookies: Sometimes cached data can interfere with extension functionality. Clearing your browser’s cache and cookies can help.

4. Restart Browser and Device: After reinstalling or updating, restarting the browser or your computer can resolve lingering issues.

5. Toggle Instant Log In: If you are able to access the app settings, toggling the Instant Log In feature off and then back on has helped some users.

6. Ensure Software is Updated: Make sure both your browser and True Key app are updated to the latest versions.

If you tell me more about your exact browser and what you've tried so far, I can guide you through tailored steps. Does that sound good?