Hello,
I’ve seen references to a screen capture command/action in earlier posts. However, I can’t find anything in my GD5. Is it gone? Could come handy for prolonged test runs and other issues as well…
It is not available in GD5, sorry. Image manipulation has not been ported to web at all 
Thank you. Tough luck then.
Now we can use a action for take screenshot in games
http://wiki.compilgames.net/doku.php/gdevelop5/all-features/screenshot#screenshot_extension