I think the intended method of using this API is to use apis from within a mobile app to make the request transparently (and ensure mobile data is used to avoid users having to manually disable wifi), but the person in the article is just generating a QR code that you have to scan so I assume you would indeed have to disable wifi by hand each time which would make it more trouble than its worth.
I had no idea mobile network operators were tacking on my phone number to requests though (presumably unsecure http only but still)...