Hello,
1. Currently the only locations for Document AI OCR are US and EU, you can decide where to send them by using:
Where LOCATION can be either `us` - United States or `eu` - European Union
2. The Google Document API has a page about the Data usage, please read all the points in there as it will answer your question.
Includes answers to the questions:
Will Google share the document I send to the Document AI API?
Does Google use my data for improving Document AI?
Does Google claim ownership of the content I send in the request to Document AI API?