Sending a user upload via the xMatters API

Question 

How do I upload users programmatically using a .csv file? 

Environment

All versions of xMatters On-Demand

Answer

The documentation covers how to do this via CURL:

curl https://acmeco.xmatters.com/api/xm/1/uploads/users-v1 \
    -X POST \
    -H "Content-Type: multipart/form-data" \
    -F "name=Upload 1" \
    -F "file=@user_data.csv" \
    --user $USERNAME:$PASSWORD

It's important to note the @ in front of the filename (without this the request will fail).

Here's what it would like look using Postman:

Don't forget to choose File format for the request: