patch https://sandbox.elationemr.com/api/2.0/bills//
The main use cases for bill update is for marking bills as processed or marking bills as failed but you can also use this endpoint to PATCH general information on the bill.
To mark a bill as failed, you should at minimum provide billing_error, which is the human readable error that will be visible for the user to see. If you wish to provide some more details on the error without showing it to the user (e.g. a traceback of the error to help debug), you can fill out billing_raw_error.
To mark a bill as processed, you have to provide both ref_number and the billing_date fields when the bill has been processed. When ref_number and the billing_date are provided, the bill is considered "Billed" and cannot be updated again.