For security reasons we employ two factor authentication which means when you reset your account or register for the first time you will receive a text with a 6 digit code to enter. You should make sure that your phone and plan supports text message delivery. Delivery speed or the receiving of texts can vary depending on service and location, so your network provider may struggle if you are in a remote area or abroad.
Try not to make multiple attempts at generating a security code otherwise you could receive several codes at once if you have slow network service, make one attempt and wait 5 minutes.