Broken Home button on Old Ipad. Just swipe up from bottom screen to simulate the home button
Disclaimer: Boring Video.
To get passed the lock screen on an older ipad with a broken home button. You can attempt to try the following (you need at least ios 12).
1. Press the power button to turn on your ipad air
2. From the very bottom of the screen swipe up. This will simulate a home button press. That's it.