I've got a working .wav here have tried a few utils to convert to .tap without and luck. If there's a good util that works let me know and I'll give it a go. BTW I'm on a x86 so RVM no use.
Thanks. You can use audio2tape, which is one of the Fuse Utilities (an optional download, separate from the Fuse emulator). I've just used it now on the .wav that you've just uploaded, and it produced a perfect .tap file on the first attempt. I note that someone else has already offered to send you a conversion, so I won't do it myself (though I did with one of your previous games) – but if you need it, just let me know. NB You don't really need a .tzx file since only a standard loader is used; a .tap is perfectly sufficient.
Here's a download link for the Fuse Utilities for Windows: Fuse Utilities v1.4.3 – and you'll find audio2tape and its documentation in the collection.
Regarding x86 and RVM being 'no use', you're mistaken. RVM is available for Mac, Windows and Linux (and there's even a build for Raspberry Pi now). Give it a whirl. Whether it's an emulator you want to use in general is a different matter (personally I still prefer Fuse with its no-nonsense interface for general use), but RVM is certainly VERY useful for creating tapes, I find. Surely, just saving out to a distributable tape file is preferable to having to go through audio file conversion.
Here's RVM: https://www.retrovirtualmachine.org
NB There must surely be plenty of other emulators that can save tape files. (Fuse is supposed to be able to, but I've always had trouble with doing it in the Mac version.) RVM can't be your only choice. I suggest it simply because I've found it useful for doing that, and I like its interface for creating tapes. It makes it pretty easy and lifelike.