There's no keyboard on most Android devices!
Getting a screenshot depends on which device you are using. For example, on my Asus tablet, I hold down the 'switch app' button to get a screenshot, but I think I had to enable that in the settings somewhere.
If you do a search for your device name and the word screenshot (or screen shot) on Google, you should get some results.
Alternatively, just use a camera to take a photo and upload the image.