Unrecognizable iCloud email piped up while trying to sign up to track a purchase

I was tracking my purchase on Simple hair color, Pressed the app on there email, pressed the sign in button, and email and password Popup was opened but an unrecognizable email popped up where it's usually mine that does???This Emil that popped up was strange usually when I download an app to sign up it asks for your email address and to include a password, but the email was NOT MINE!!! This Email below popped up in the box...???

****@icloud.com

[Edited by Moderator]