It's a VCV voicebank, so you'll need to ensure that notes are converted to VCV format. In classic UTAU you can use a plugin like iroiro, and in OpenUtau you can select the appropriate phonemizer to automatically convert all notes.
For the voicebank you'll also need the 滑 suffix. For classic UTAU you can simply add this to the lyric of each note you want to trigger the alternate voicebank. In OpenUtau you'll need to configure an additional voice color, and map the suffix to all pitches. Then you can select the smooth voice color for the individual notes you want to apply the suffix to.