If you're using page-based billing, your files need to be tied to an approved purchase order (PO) through an Enterprise subscription. Here's how to do that through the API.
Use:
GET /v1/user/purchase-orders
This returns a list of your POs and their current status.
approved status with available pages can be used.When uploading via:
POST /v1/external/user/files
Include this in the request: