Can't find AutoUnattend.xml?
I have no idea the model/year of the OP's Mac, therefore this answer is based what I think would work.
The Windows Support Software provided by Apple for the newer model Macs no longer includes an AutoUnattend.xml file. This file is not required to install Windows 10. With respect to this answer, you can skip step 3 and replace step 7 with the step 7 given below.

Enter the command below to start the Windows installation.
setup



When you finish installing Windows, you will have manually run the Windows Support Software installer, as explained in step 10.

Note: The questions and answers linked to your question were created at a time when Apple was having the Boot Camp Assistant install Windows 10 with a separate recovery partition. The newer versions of the Boot Camp Assistant no longer do this, which significantly simplifies the installation procedure from what I previous posted.