Method Of Payment in CX Sales Cloud

Hi everybody, 

we are working with Fusion (CX) Sales Cloud and we are using CPQ as well.

We are facing with a internal discussion as the “Billing Account” and related “Payment Methods” are not clearly an entity managed in Sales Cloud. We have a requirement to check a “Payment Method” since the Customer subscription so we need to add the Billing Account information along the subscription process.

We see a “Billing Account” tab can be added under “Account” page, therefore: 

• how to add this tab (which Roles are needed)?
• which data can be added/managed by means this tab/entity?