If you are asked to input credit card information in order to sign up for, or continue to access, your account, you’ve either entered an area of Grammarly by a link other than what is shown in this tutorial or you’ve used a non-TU email account. Your best course of action in this case is to contact Grammarly customer support through their Support area at the following link:
Please note that there is a contact form available to submit help desk tickets to Grammarly. There is currently no phone-based system available for support requests. The library can also delete your account so that you can try to recreate it. You can contact us at email@example.com. We are unable to retrieve lost passwords.
Try looking here!
Other guides which may interest you:
Tiffin University subscribes to these services for faculty and student use.