Is it possible to put an older version of iOS on an iPad?

Question

iOS

I bought an iPad mini for my parents from my hands, for some reason the former owner put iOS 9, which lags on the old iPad,
I want to put 7 or 8, but it’s impossible to do it officially (the apple company loves its users)
Is it possible to reflash the iPad somehow differently to old iOS?

Answer 1

It is forbidden. Generally it is impossible.
https://4pda.ru/forum/index.php?showtopic=395459

iOS 8, iOS 9, iOS 10
Rollback for iPhone (4S*, 5*, 5C, 5S, 6, 6 Plus, 6S, 6S Plus, SE, 7, 7 Plus), iPod touch (5G, 6G), iPad (2*, 3, 4, Air, Air 2), iPad Pro (9.7, 12.9), iPad mini (1, 2, 3, 4) -> not possible, even with SHSH certificates