I tried it too but he asks me for a phone number from China which for me is impossible, I don't know if it happened to someone else?
There should be something you can tap on on the left side of the country code number that gives you a drop down menu and it's got a bunch of different countries. You just need to figure out which one translates to your country's name, and then you'll be able to enter your number and it should work.
Mine worked with a Canadian number. Once you get to the payment option though, I've no clue how to get it to work on my phone.