Very nice tool! However, I think it is not always correct. For example, lake Trasimeno, in Italy, is endorheic (or maybe cryptorheic), but seems to discharge into river Arno from this website: https://river-runner-global.samlearner.com/?lng=12.098864773....
I am pretty sure that path is not possible: it seems that the water would flow out of Trasimeno through the Anguillara torrent, but according to the Italian Wikipedia the torrent flows into the Trasimeno (https://it.wikipedia.org/wiki/Anguillara_(torrente)). According to the English Wikipedia it might be that Trasimeno has an outflowing canal, but that should flow into river Tevere (https://en.wikipedia.org/wiki/Lake_Trasimeno), so their data is wrong anyway.
I am pretty sure that path is not possible: it seems that the water would flow out of Trasimeno through the Anguillara torrent, but according to the Italian Wikipedia the torrent flows into the Trasimeno (https://it.wikipedia.org/wiki/Anguillara_(torrente)). According to the English Wikipedia it might be that Trasimeno has an outflowing canal, but that should flow into river Tevere (https://en.wikipedia.org/wiki/Lake_Trasimeno), so their data is wrong anyway.