Step 1) Login to Google Webmaster with your Google account.
Step 2) Click "add a site to get start" to fill in your own domain.
Step 3) Go to "alternate methods" ， choose "add a meta tag to your site's home page" and Google will give you a meta name and content.
Step 4) Now it's time to add meta tag to your miiduu store. There are two ways to reach this goal:
Step 4a) Visit Miiduu App Store to install the app "custom meta tag".
Then configure this app through miiduu admin menu: App Store → Installed App. Fill in the meta name and content you got from Google. See screenshot below.
Step 4b) Alternatively, go to menu: Design → Template & CSS Edit to add meta tag into your template file (<template_name>/common/header.tpl)
Step 5) Finally, go back to your Google Webmaster account and click "verify" to finish the process!