BTT Gone Missing

Hi all.

I've just purchased BTT and I think I created a new Touch Bar shortcut with it, but I haven't been able to use it yet. With app window open the app icon appeared in my dock, of course, and so to remove it I did what I normally do, hit Command & Q to quit it.
I expected that the app icon would remain in my menu bar, but it vanished. Furthermore, when I look in my applications folder there is no sign of it there either, even though I moved the downloaded file there before double-clicking it.
Has anyone any idea what went wrong here? Has anyone any idea where my app has gone please?