API hosted page integration

API hosted page integration

Hello,
We have created a product that has 3 subscription plans (basic, small business, and enterprise) and we want to create, change, cancel subscriptions from our website via Zoho APIs and without SSO. 

I have checked your documentation for the API hosted page in the following URL: https://www.zoho.com/subscriptions/api/v1/#Hosted-Pages_Create_a_subscription 
but I am confused about registering a new user to one of our subscriptions because API doesn't include credit card info as input parameters. how can we achieve that?