That might be because your Google email address is different from the email address you used to sign up for the course.
Don’t worry, there’s an easy way to retrieve your purchased course.

Go back to the sign in page, and sign in using the same email you used to purchase your course. 

On the next screen, you’ll be prompted to enter your mobile number, which will help us link your mobile number to your account. Once you’ve verified your mobile number, the next time you’ll be able to log in seamlessly using your mobile number and a secure OTP.