To allow Google access to your content, make sure that your robots.txt file allows user-agents "Googlebot", "AdsBot-Google", and "Googlebot-Image" to crawl your site. You can do this by adding the following lines to your robots.txt file:
User-agent: Googlebot
Disallow:
User-agent: AdsBot-Google
Disallow:
User-agent: Googlebot-Image
Disallow:
Learn more about the Robot Exclusion Protocol
Google may use information obtained from any of these or other various user-agents to improve our Google Ads systems.