It doesn't, but does support unicode text, so use just another site and then copy-paste the result here. :)
I have noticed that many cloud based TTS actually work fine with unicode which was surprising. I know google one does and it sounds way better than whatever comes in as default on Ubuntu (Orca).
Keep in mind that screen reader and voices for it are different components that could be mixed. Both could be instructed to treat unicodes in whatever manner necessary, but it is labor intensive and euristics usually has some dubious results.