How to cancel a call with XCTest for iOS 14

Hi I'm writing some XCTest in Swift for iOS 14.

Back in iOS 13 the springboard handled the call screen and you could end a call with

let app = XCUIApplication(bundleIdentifier: "com.apple.springboard")

app.buttons["End call"].firstMatch.tap()

However the springboard does not seem to contain the end call button for iOS 14! So how do you end a call in iOS 14?