How can I verify my account?

I'm a newbie at Ingress. I see other, more experienced players have a silver badge saying that their account is verified, but I can't find the corresponding feature in the application. How can I verify my account and get this badge?

I have read that I should be asked for verification when reaching level 2, but I'm already at level 5 and nothing of the sort happened.

Solution 1:

Niantic has removed the verify option since some weeks before it spun from Google. See the comment of Niantic in this post: "We've turned verification off."

Support page:

As of September 2015, we've removed the verification feature in Ingress, and it is no longer possible to receive the Verified Agent medal. All features that previously required verification will still work for new Agents that have never had the option to verify.

Solution 2:

I'm now L7, and i never had the opportunity to verify.

ingress G+ said it's an error right now and they're working to fix it. Posted within the last 60 days.

they're working on it.

Solution 3:

When you reach level 2 you'll be asked to enter a verification code that will be sent to you via SMS to verify that you are, in fact, you.

Once that's done you'll automatically get the 'Verified' badge and your inventory space will be expanded from 200 to 2000 items.