One of the options to create and also sign in to Lifesum is using the option to log in with your Apple ID in two different ways:
  1. Showing your actual email address connected to your Apple ID under Settings -> Account Settings in Lifesum.

  2. Using Apple’s "private email relay" service and hiding your email address under Settings -> Account Settings in Lifesum (the field will show an email address created by Apple ending with "" (emails will then be routed to the Apple ID’s verified email address).
The email address you are using for Lifesum can be found under Settings -> Apple ID -> Password & Security -> Apps Using Your Apple ID -> Lifesum.
Please find more information here: