If you are using a service like Google Analytics, they require that you claim your site to verify ownership. Follow these instructions to add the Google meta tag.
Note: You will need to add the meta tag to the page that is set as your site homepage. Click here to learn how to select your site homepage.
Whether you are using a landing page or your store as the homepage, click Edit Code for the theme.
For Website theme:
Open the theme.liquid file in the Layouts folder:
For Landing Page Theme:
Open the index.liquid file in the Templates folder:
You will notice the <head> tag at the top, paste the meta tag just below the <head> tag.