Great, thanks, I was able to upload with an existing DOI using the API.
What I really meant by "automatically" is this: ideally, I would give dataverse a folder of pdfs of published papers, and it would fetch / create the metadata it needs (authors, abstract, etc) and add each paper as a dataset. Zotero can do this... but I guess it isn't really a common use case for Dataverse.
If dataverse cannot fetch or extract the metadata for me, is there a way to import metadata to Dataverse from a format like BibTeX or Endnote? Or similarly, can I convert a BibTeX file into a dataverse .json or DDI to use with the API?