Foxtel tend to provide people with a means to order via their internet connection these days. IQ3 boxes have WiFi built in and when they last installed an IQ2 box for a family member an ethernet over power adaptor was provided to bridge the gap.
If you currently have Foxtel from Optus it would be via Optus' HFC (Cable) network which is being decomissioned. When you switch over to the NBN, you'll also be required to switch over to Foxtel Satellite.
I'd contact Foxtel directly to discuss the options available to you.
____________________________________________________________________________________________________________________________ I do not represent Optus. The views, opinions and advice expressed in my posts are my own