Your button is covered by the keyboard
The solution is simple: While the keyboard is closed , change the button's location on your screen higher up.
Tap and hold the button to drag-and-drop it to a location you're comfortable with.
Button is covered by a system interface element
If your button is stuck behind a modal, date picker etc. there's nothing you can do — those are system interface elements and everything goes behind those by definition.
Try reporting a bug alternatively 🤳 by shaking your device or by taking a screenshot . If these two don't work either, get in touch with your app administrator and describe the situation to them — they'll be able to help you.