1)

Go inside the Workflow Guide and click on "Add Step"

2)

Click on "Image Step"

3)

Click on "Capture Screen"

4)

Click the checkbox if you agree with the message

Then, click OK

5)

Press "Shift" key and "P" together 

6)

This is how, your screen will be captured in no time!

Also, you can set the capture delay time (in secs) before capturing the screen