I downloaded the app and there isn't a link to create an account. The displace asks if I already have an account and the field to sign in.
The login for your Nurture Parent app will be the same login username and password that you created for the payment portal.
1. Make sure that the email address you are using is the same email address that is used for the Nurture Payment Portal
2. Make sure that your email address is using all lower-case characters. The login field is case sensitive for security purposes. For example: firstname.lastname@example.org