get https://api.piriod.com/purchases//finalize/
Finalize an Purchase object. When the Purchase is finalized, it is validated with the tax agency if the document type has tax regulations. After finalize you will no longer be able to update your purchase data. The status attribute of the purchase object will become to finalized. The local_file attribute of the Purchase object will have a url to get the file that was sent to the tax agency, normally it is a file with an XML extension.