How to take a screenshot on iOS devices?
To take screenshots on your iOS device please follow these steps:
On an iPhone 8 or earlier, iPad, or iPod touch
Press and hold the Top or Side button.
Immediately click the Home button, then release the Top or Side buttons.
In iOS 11, a thumbnail of your screenshot appears in the lower-left corner of your device. Tap the thumbnail to add drawings and text with Markup, or press and hold the thumbnail to share the screenshot. Swipe left on the thumbnail to dismiss it.
To find the screenshot you just took, along with ones you've taken before, go to Photos > Albums and tap Screenshots.
On iPhone X
Press and hold the Side button on the right side of your device.
Immediately click the Volume up button on the left side, then release the buttons.
A thumbnail of your screenshot appears in the lower-left corner of your device. Tap the thumbnail to add drawings and text with Markup, or press and hold the thumbnail to share the screenshot. Swipe left on the thumbnail to dismiss it.