Unity UI Handling rounded corners in the iPhoneX

I'm working on a VR app on IOS which needs to support both classic iphone as well as iphone x.

I have an over-lay button which sits on top of the VR. My problem at the moment is that the scaling and position on the iPhone X is actually within the rounded corners of the physical device

an iPhone 6 or 8 looks like this:



an iPhone X looks like this:



now in the second image the button is actually hidden under the rounded physical edge of the device.

I can't find any current in-built UI element which allows for canvas to be resized based on the SAFE AREA of the screen.

Is there an existing SAFE ARE support in unity (this project is v5.5 by the way)? Or do I have to write my own?