Create a file

Creates a file resource and returns the upload target for the bytes. Upload the raw bytes to `upload.url` using the returned method and headers, then call [Complete a file](api:POST/v1/files/{file_id}/complete) to mark the file ready. Until the file is `ready`, you cannot attach it to an authorization. File creation does not link the file to anything. Attach a `ready` file to an authorization with [Attach a file](api:POST/v1/prior-authorizations/{authorization_id}/attachments). ## Returns Returns the pending file and a single-use upload target.