I have a user who has this problem in their IphoneX iOS 13.2, he has no "done" button to accept a comment because seems like he is using SwiftKey app for custom keyboards and in my testing IQKeyboardManager is doing good.
So SwiftKey app has a problem with IQKeyboardManager, the done button of the toolbar is not showing up and either the "dark theme" on the keyboard.
Any suggestions?
You can double check this on that instance.
IQKeyboardManager.shared.enable = true
IQKeyboardManager.shared.enableAutoToolbar = true
IQKeyboardManager.shared.overrideKeyboardAppearance = true
IQKeyboardManager.shared.keyboardAppearance = .dark