class MyDialog : androidx.fragment.app.DialogFragment() {
...
    override fun onResume() {
        super.onResume()
        // AlertDialog sets flag to prevent showing keyboard if custom view doesn't have EditText
        // It of course cannot be detected with Compose (all composition is dynamic)
        // So clear flags, show keyboard
        // <https://stackoverflow.com/a/62767205/420412>
        val window = dialog?.window
        if (window != null) {
            window.clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE)
            window.clearFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM)
            window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE)
        }
    }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
        return ComposeView(requireContext()).apply {
            setContent {
                MyComposable()
            }
        }
    }
}