How to use python to get screenshot of simulator in Addon?

hello guys,

I make my own Addon and it already have a button in my new interface as follow

How can I get the screenshot of the simulator when I press the Export button ?

I’m thinking that if I can use the Image function(following picture), I can full fill this function. But I don’t know how to call this Image function. Could someone can help me for this question?

Thank you.