http://borp2ggcrfzhheho2ysverkd3xen6tnrjd42ovpvlslkjmyqmnpbtyid.onion
Note that it's a hashtag (#) and not a question mark (?). This is because TruMix works entirely in the browser and no processing occurs on this server. This makes it more private for clients so there's no single trusted party that knows about the entire mix.