First, if you have a domain name connected to your site, make sure you have a preferred site address selected. In the site editor, go to the Settings tab > Site Address in the left sidebar and choose a preferred site URL from the drop-down box.
Click 'Add A Property' > 'Add your site URL' (the preferred site address).
Select the ‘Alternative methods’ tab and choose ‘HTML tag’, then click 'Verify'.
Copy the full strip of code and log into your site editor in a separate window.
On the Left Sidebar select the 'Settings' tab and click the 'Site Integration' option.
Click the Google Search Console 'Connect' option, paste the meta tag into the box and save.
You should see a green tick showing that the setup is successful.
To complete the setup: You must go back to the Webmaster tools page in Google and click 'Verify' to complete the setup.