The first email shown in the article ends with the call to action of "get more storage" and a link. Pretty obviously that would be buying additional space, not getting it for free.

(But it would cost something like $5k-10k/month, not the ~$10/month that he seems willing to pay.)

The second one has a link labeled "free up or get more storage."

I suspect it links here: https://support.google.com/a/answer/12005619?sjid=1774262812...