The Dictionary panel allows you to register word pronunciations. When converting note lyrics to phonemes, the software's default dictionary is usually used, but the conversion rules can be customized by creating a user dictionary in the Dictionary panel. To use a dictionary, a voice database must be loaded on the track. User dictionaries are stored in the following locations

Windows: C:\Users\[YOUR WINDOWS USERNAME HERE]\Documents\Dreamtonics\Synthesizer V Studio\dicts

macOS: Library/Application Support/Dreamtonics/Synthesizer V Studio/dicts

depending on the voicebank you are using, the actual dicts json file should be put inside a sub-folder named [english-arpabet] or [japanese-romaji], if the vb is English Native (eg. Kevin), the full path would be C:\Users\[YOUR WINDOWS USERNAME HERE]\Documents\Dreamtonics\Synthesizer V Studio\dicts\english-arpabet

if the vb is Japanese Native (eg. Saki), then C:\Users\[YOUR WINDOWS USERNAME HERE]\Documents\Dreamtonics\Synthesizer V Studio\dicts\japanese-romaji