Trying to import an XFA doc into a PDF document as input data, via python

We can do this via Adobe Acrobat without issue (Menu -> form options -> import data -> zzz.xml), but we need to be able to do this programmatically. Looking through the SDK documentation in your 'pdfservices-sdk' (https://opensource.adobe.com/pdfservices-python-sdk-samples/apidocs/latest/reference/index.html) and I can't find anything to import xfa data in from. Anyone tackle this before/have any thoughts?

I've been trying DocumentMergeJob, but that may not be what I am looking for.