Tap the portrait icon in the bottom left corner of the lists manager:
Select "Create an account":
Fill out "Email", "Login" and "PIN" fields, and tap "Done":
All these fields are required. Note that your login and email should be unique, i.e. you can not use the same login or email for several accounts. Besides, you are offered a random 4-digits PIN – you can leave it as is, or change it to your own 4 digits.