If you signed up for a ShopBack account using an email address:
Select 'Use email address'.
Enter your email address and password and click 'Sign In'.

If you have signed up for a ShopBack account with Facebook:
Select "Continue with Facebook".

If you have signed up for a ShopBack account with Apple ID:
Select ''Sign in with Apple''.

If you require any further information, you can contact the ShopBack Help Center through friendly live chat agents LiveChat! or through e-mail at  ShopBack Help, every Monday - Friday from 8:30 am - 6:30 pm (except public holidays).