Adding used iPads to our inventory

We ordered some used minis to replace broken or dead full size iPads. I have just got them all set up with apple id and wifi, now trying to install Practiscore app and saying it isn’t compatible. They are older and max at iOs 9.3 or so. I have other ipad minis running this iOs and practiscore just fine. Is there anyway for me to get the older version of the app on these devices?

@Edward_Sendele
Oh I wish you would have reached out to us before you bought these.
Apple has discontinued support on gen 1 iPad minis. They are not allowing the gen ones to connect to the Apple store anymore so there is no way to get the apps. Actually any apps.
If you can return them do so and see about finding some used Gen 2’s they should give you a couple more years of access.
Sorry.