You can use the shortcut keys Win key + Shift+ S to open Snip & Sketch. Select the area you want, and a notification from Action Center will pop-up saying that the screenshot has been saved to clipboard. Click the notification, and ta-da, you get the screenshot for editing.
Otherwise while doing with the app, the screenshot is automatically taken to the app's window. So after selecting the area, go to the app window to get it.