Press the top button and either volume button at the same time to take a screenshot
Use AssistiveTouch and tap Device, then More, then Screenshot
Enable Guided Access in Settings, then triple-click the top button to lock the iPad to one app
Use a screen recording app or built-in Screen Recording to capture a static moment if needed
To stop the screen from changing, turn on Auto-Lock in Settings and set a longer time
To keep the display on, open Control Center and disable True Tone or Night Shift only if needed for viewing consistency