How to get iframe src?

How to?
#1

I simply wants to get the iframe src url. But I cannot get that using selectors.

Url: https://gdcvault.com/play/1023750/-Is-that-Me-Identity

#2

You'd usually need to look at the source (Chrome inspector) to figure out the url. Try:

Type: Element Attribute
Selector: div.videoDisplay > video
Attribute: src