Once again, as Lotus Pilot already has explained.
This is never going to happen for these 8-10-year old iPad models.
Your over 8-year old, iPad Mini model is too old, now.
Apple ended support for 8-10 year old iPads, at least, over 3 years, ago.
The internal hardware in that iPad is too old, too underpowred and completely incompatible with all later versions of iOS/iPadOS.
Virtually, all third party iOS app developers ended/stopped/abandoned supporting these old iPads over two years, ago.
There are virtually, NO MORE older iOS 9 or 10 compatible apps available from the Apple iOS App Store, any longer.
There has been NO WAY to get older apps for these aging iOS devices for the past two years, now.
Simply put, your 2012, 1st gen iPad Mini is too old and obsolete now.
Also, being very old, there is NO device trade-in value for these, either!
Sorry.
If you need/want an iPad with an up to date iPadOS with access to current, updated apps, then you really need to seriously consider a new iPad model OR a much “newer” , used iPad model capable of running the latest iPadOS versions.
There are plenty of newer, older iPad models that can run the latest, current versions of iPadOS.
Sorry & Best of Luck to You!