You can see and change your subscription plan in Settings > Plan & Billing.
Step 1. Go to Settings > Billing
Step 2. Include the email address that you used to subscribe
Insert your email address with which you created the subscription to receive the confirmation mail to sign in to billing.
Step 3. Copy and paste the code
Copy the code that you received in your email and paste it on the page that requests the confirmation code.
Didn't receive the confirmation code in your email?
These might be the issues and solutions:
You might not be using the correct email address to access Billing. You need to use the email address that is associated with the premium account. This is the email address that is used to sign up for the premium account. If you use a different email address, you won't receive the confirmation mail.
The email might have landed in your spam mailbox. Please check your spam mailbox to see if the email
It could take a few minutes before you receive the confirmation code. Please wait a moment and see if the confirmation email arrives.
Step 4. Access Billing
See and change your plan, billing and invoices.