Google Search Console (formerly Google Webmaster Tools) is a service that you can use to see information about the search traffic to your site, what keywords are being used and potential errors on your site. Google Search Console also allows you to submit a sitemap to Google, which helps in indexing the site.
Get started with Google Search Console
Go to Google Search Console here and sign in with your Google account. Once signed in, you can add a new web property to Google Search Console.
You can add your site in two different ways, but by default it is easiest to choose to add it as a URL prefix.
That way, you can copy an HTML tag that you then add to the shop administration.
Copy the meta tag and paste it into the "HTML Head Area" field on the Settings > General Settings > Advanced settings page and then "Save". The page cache then needs to be updated on the Settings > General Settings > Page cache page by clicking the "Update immediately" button. Once the tag has been saved in the administration and the page cache has been updated, you should be able to verify the site in Google Search Console by clicking the "Verify" button.
Adding a sitemap
Once the shop has been added as a property in Google Search Console, you can also add the shop's sitemap to Google Search Console. If the site was added correctly, you just need to enter sitemap.xml in the field and click "Submit".