No problems using UtaFormatix.
Here’s my route again, if someone doesn’t know this already: Export MusicXML from Dorico and import it to UtaFormatix, export Standard MIDI [MIDI – Mid (Standard)] from UtaFormatix and upload the MIDI to Cantai Web Renderer. No MuseScore in my case, that is. I find this way just a little bit more comfortable. 
UtaFormatix is a fast and convenient web application for converting projects among singing voice synthesizer softwares such as VOCALOID, UTAU, etc. So no need to install (and learn the [easy] use of), say, MuseScore, if you haven’t got it already.
All of the above, because Dorico does not export lyrics with MIDI, but of course does with MusicXML.