sbp to trk conversion is typically searched by users that get .sbp file and want to use in navigation software or device, for example CompeGPS.
The only way how to convert these files is to use the same software in which these were made in first place, GPSBabel, considering that .sbp files are special exchange format from this software anyway. If you have issues with export of .sbp files, it might be best to reach out to the GPSBabel online community.
Actually might be related to export of tracks from Locosys GT-11/BGT-11/GT-31/BGT-31 GPS receivers in which case GPSBabel is still the best choice how to convert sbp to trk.
Updated: August 14, 2023