Upload your invoice documents using the /api/services/app/Document/Create service. Ublion API accepts currently, JSON, HTML and Base64 (max. 2.00 MB each).
Note, the ublion end user interface has a built in file to base64 decoder.
The service will return an Ublion internal id when your upload a document. You can use this ID to find documents states etcetera.
The service is fully configurable but you only need 3 parameters.
The default API rate limit lets you upload 500 documents per hour, 2,500 documents per day, 10,000 documents per week and 50,000 documents / month.