Does Shiprush support Unicode?

Hi,
I am a longtime Shiprush for stamps user, but recently need to start sending labels that have Japanese Kanji in the data fields. When I try to copy/paste Kanji into shiprush fields, I get question marks " ???" Does Shiprush not support Unicode? ie. will I not be able to use Shiprush to create labels with Kanji Characters?

thank you for your help.