If your iPad Home button isn't working restarting, resetting, or removing protective cases are good starting points.
ALL IPADS: HOME BUTTON NOT WORKING, STUCK, STICKY, LAGGY
A-MIND For IPad Mini 4 A1538 A1550 Touch Display Panel
iPad Air 2 Home Button (Repair Included)
5 Easy Ways to Fix iPad Stuck in Guided Access
Why My iPad Home Button Collapsed After Screen Repaired?
iPad Mini 4 Home Button Repair
iPad Home Button Not Working After Being Repaired – CaseMogul
iPad Pro 10.5 Home Button Replacement - iFixit Repair Guide
How to Reset Your iPad and Erase All Content
How to Restart iPhone / iPad Without Using Power Button & Home