Nokia XL is the biggest android phone offered by Nokia and taking screenshot on android phone is fairly similar. However unlike Samsung phones where you hold the home and power button together, in Nokia XL you just press the power and volume up button and the phone will store the screenshot.
So where is the screenshot stored? Well it is saved in the logs folder that is located in the root directory. If you do not fancy firing a file manager to file that screenshot you just took, just open gallery and you will easily find it there.
Just do not take a lot of screenshots on your Nokia XL as you get only 1.1 GB usable storage out of the box.