I know it’s really difficult to deal with this kind of problem but Apple software updates are mandatory for all the apps for user experience and security purposes
First try to update your iPad if you can
if you have an old model of iPad such as iPad 2, iPad (3rd generation) or iPad mini (1st generation). These iPad models do not support any system version newer than iOS 9
In these situations you can’t download apps because of the compatibility requirement unless the app offers an older version as an option for you .
I hope this helps!
have a wonderful day.