This seems to require an onNewIntent listener: NativeScript/NativeScript#2747
I've tried extending the com.tns.NativeScriptActivity as suggested in that post, but so far onNewIntent does not fire.
To be clear, the app currently resumes from a URL when the app in the background, but we are not catching the new intent to get the target url.
Be careful about trying to use an existing plugin, e.g. https://github.com/hypery2k/nativescript-urlhandler
On iOS, that plugin implements UIApplicationDelegate, but we also implement this for analytics, and there can only be one delegate.