To verify that the AMP activation has been correct:
1. Go to an article within the domain. Remember that AMP will only be present in articles, not in the home page or sections.
2. Find the AMP html link in the source code. You can easily find it by searching for amphtml using the search tool. (Command + F in your Mac)(For Windows Chrome (latest versions): F12 or Ctrl+Shift+I) .
3. There, you will find the amphtml link. Open the link and check that the AMP Validator is green. Test it in several articles to ensure that it works properly.
4. 2 days after the activation, check WebMaster Tools to ensure that the level of errors is stable to make sure that the activation has been a success.