Unfortunately, you can't verify using that site anymore :(
I already tried it a lot of times.
lol@ This site is useful for:
Getting a message when you want to keep your real phone number to yourself. When your ex-wife wants to send you a text message.
Your phone has stopped working. One of the children that assembled the phone in China made a mistake.
You only have access to the web because the NWO has disconnected you from the phone system.
You don't have a phone because you are living off the grid and don't carry a trendy tracking and profiling device.
Easiest method, get Bluestacks SW, then install Text plus and get your # to use.
A lot of numbers do not work