anchor.diff:  
   Kill Bill will now automatically charge the user on a monthly basis. You can estimate the amount which will be billed at a future date by triggering a dry-run invoice. On the main account page, in the Billing Info section, click the *Trigger invoice generation* wand (specify a date at least a month in the future).
   
  -== Using Kill Bill from your application
  +== Using Kill Bill from Your Application
   
   Now that you are familiar with the basics, the next step is to integrate Kill Bill in your application using our APIs. Our https://killbill.github.io/slate/[API documentation] contains snippets to help you get started.
   
  
positive.code: 
  Once you are ready to integrate with a real payment processor (see http://docs.killbill.io/latest/multi_gateways.html[this tutorial]), all you'll have to do is to create a new payment method for that account. The rest of this tutorial will still apply.
  
  === Creating your first subscription
  
  Let's now try to subscribe a user to the Standard plan. This is the call that would need to be triggered from your website, when the user chooses the premium plan on the subscription checkout page.
  
  
negative.code: * The Kill Bill *External key* field should map to the unique id of the account in your system (should be unique and immutable). Kill Bill will auto-generate an id if you don't populate this field
  * There are many more fields you can store (phone number, address, etc.) -- all of them are optional. Keep local regulations in mind though when populating these (PII laws, GDPR, etc.).
  
  === Adding a Payment Method
  
  To trigger payments, Kill Bill will need to integrate with a payment provider (such as Stripe or PayPal). Each means of payment (e.g. a credit card) will have a *payment method* associated with it.
  
  