Next, there is a billingAgreement.create (…) call that has just created the billingAgreementAttributes billingAgreementAttributes object. If everything is successful, we should return a billing agreement object with details about our newly created subscription. This object also contains a series of HATEOAS links that allow us to pass the next steps that can be done with this newly created agreement. The one that is important to us is approval_url. The Payment Processing Services may include functionality that enables you to receive recurring or subscriptionments from your Customers and to issue invoices to your Customers. If you use the Payment Services to submit recurring or subscription fees, you agree to comply with applicable laws and payment methods, including clear information to customers prior to the presentation of the initial fee that will be charged to them on an ongoing basis and an explanation of the method of decommissioning or terminating their recurring billing or subscription. If you use the payment services to issue invoices to your customers, you understand and agree that it is your responsibility to ensure that the form and content of the invoices comply with applicable law and are sufficient to achieve any legal or tax effects you wish to obtain. To create a one-user (or multiple-user) subscription for this plan, we need to billingPlan.id on the account ID (billingPlan.id above), that is, store it in a place that can be easily referenced.