welcome to the forums.
VOA is listed within Radio Roku as "Voice of America", you will thus find it under this name if you search for it with the remote.
The station, however, will not play on the SoundBridge because VOA's "experts" provide an ASX playlist file (the one DerekHelps posted) which is completely incompatible to most hardware and software players (except WMP). Furthermore the ASX file contains a stream URL that cannot be used as it contains a temporary token which expires once you stop listening.
To cut a long story short: VOA do not want you to listen to their streams on a device like the SoundBridge. The station should thus be removed from Radio Roku.
SoundBridge M1001 and M1000 • Clint L1 (retired) • DNT IP-dio (retired)
Google Chromecast • Amazon Fire TV • Amazon Echo and Echo Dot