Accessing the UKG Pro API

I was helping out IT this week with an automation task they had: they want to sync the data in UKG (an HRIS platform) with the data in the IdP. The problem was, nobody's documentation was very good and left out important details, and Google was almost no help either. Hopefully someone else can stumble their way onto this page and get going quickly.

bash curl -H 'Accept: application/json' -H US-CUSTOMER-API-KEY: xxx' -H 'Authorization: Basic base64(username:password)' https://hostname/personnel/v1/employment-details