How do I enable Javascript popups in WebView?

I am new to IOS programming. I am using Xcode 9.~. I have placed a WebView control on my storyboard and have connected it with code in the viewcontroller. I have connected to a URL. When the app runs it goes to the correct address, but that address has a link that goes to a javascript popup. The WebView then becomes blank and no further links or anything is displayed. For my app I need to display the popup so the user can continue with their experience. Any help in this direction will be greatly appreciated!

How do I enable Javascript popups in WebView?
 
 
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