hi,
When an email is sent to a recipient, it is the recipient's information that is inserted in the email.
The notification emails are sent to the admin, so the admin information is inserted, not the one of the user triggering the notification.
If you want to insert the user information instead, you need to specify it here:

Note that custom fields might not be available in all notification emails. For example the "When a new user is created" notification is sent before the custom fields values are stored.