Not sure how long this has been going on for but Sky now have a loyalty scheme in place called Sky VIP for Sky customers which among the prizes has free tickets for sporting events including EFL Championship matches.
All the matches for October are now booked up but they were showing the Sheff Utd (A) and Middlesbrough (H) fixtures as events you could attend, so presumably they’ll have more fixtures released in due course.
You’ll need to download the My Sky app to access it. One to keep an eye on.