A phone number is required to create a Core account, and to log into the app, in order to verify your identity.
Most international numbers will work just fine: when entering your number in the app, just backspace to delete the “+1” that’s displayed by default, and replace it with your country code instead. Then enter the rest of your phone number.
Although you can use international numbers to create your account, we currently only offer shipping of our products to the U.S..