How does a screen capture on the Huawei P9 lite?

How do I take a screen capture on my phone? I can take screenshots as normal with the Off + Volume Down key, but screen shots with Off + Volume up will not work. Do I have to change anything in the settings?

For a screenshot, the "on-off button" and the "volume-down button" must be pressed for about two seconds.

Press the Power button and volume + simultaneously for approx. 2 seconds. Then HD SD will appear for the recording quality. (HD = better quality but need more memory) The recording then starts in 3 seconds, you can see on the screen. The recording button will be shown at the top left. If you tap on this, the recording stops.

With me, only the volume menu opens: / Do I have to set something in advance?

However, Sound + Power button combo does not work though: / Silent + Power screen shots work fine

Hmm with me it was so you can even look in the settings.