This module provides an easy way for websites owners to instantly inform search engines about latest content changes on their website.
More information about IndexNow protocol you can obtain on official site.
Administration page is available via menu Administration > Configuration > Metadata > IndexNow (admin/config/metadata/indexnow).
- generate or create your own IndexNow API key as described below "IndexNow API key" field;
- select your prefered search engine;
Please note: starting November 2021, IndexNow-enabled search engines will share immediately all URLs submitted to all other IndexNow-enabled search engines, so when you notify one, you will notify all search engines. - select what content types to submit when you create or update nodes.
IndexNow administration page:

When you save the settings, a text key file to verify the ownership of the site will be generated for you automatically.
Now, every time cron runs, the latest content changes will be automatically sent to all participating search engines. Thus, multiple edits of the same node do not result in multiple submissions.