vocabularyFileUri

The Amazon S3 location of the text file that contains your custom vocabulary. The URI must be located in the same Amazon Web Services Region as the resource you're calling.

Here's an example URI path: s3://DOC-EXAMPLE-BUCKET/my-vocab-file.txt

Note that if you include VocabularyFileUri in your request, you cannot use the Phrases flag; you must choose one or the other.