Hello,
You can find an example on the same API page and all options explained. From this page:
source: Path to the docx.
target: Path to the resulting docx.
You just need to set the template with the DOCX to be changed as source, the output DOCX as target and the last option (data) is an array with the new data. We recommend you to check the example available on the API page, that is the same than the included in the package (exmaples folder).
Regards.