For the love of God, please don't make visiting this forum conditional on a cell phone signal!Most commonly, you'll get a text with a string of numbers to enter. It slows down the login process by a minute but it increases the security of your login process by orders of magnitude.
Something went wrong on my phone about 2 weeks ago so that it won't call or text over WiFi. I couldn't communicate with my wife until we got to Panama yesterday. I tried to use WhatsApp and they want to verify my number by sending me a text. If I could text, I wouldn't need WhatsApp!
Please remember us little guys that go weeks and sometimes months without cell phone service if/when you set up any 2FA.