In this model, you wouldn't await the user clicking OK, but exiting the modal. The promise only resolves "user took a decision", not the actual choice they took.

The result then contains if the user clicked OK, Cancel, [X] to close the modal or any other state transition that you may have added to that dialog. The recipient (not necessarily the caller that initiated the dialog, in case you chain the responses) can then act accordingly and presumably triggers a different action on OK then the other state transitions.

You return a different result (i.e. the Promise resolves to a different result). The calling code can then decide what to do with it.