There is no trial version which acts as a VST plugin currently, this is planned for Dorico (coming into Musescore soon apparently.)
Did you find the Cantai site?
Are you aware of our other thread here?
This shows the process:
Summary: Dorico xml to Musescore or UtaFormatix, midi export to Cantai render page, download the audio files.
Cantai are working on using musicXML for lyrics as import for rendering (as well as midi), but after it is integrated as a VST, it will no longer be as necessary.