Hang on a second, there's a couple things you need to know.
One, to play FreeSpace 2 with FreeSpace Open, you need to actually own FS2. You can get it on Steam or GOG, the rest of our infrastructure can deal with both.
Two, wxLauncher is deprecated and no longer in development. We now use a program called Knossos (which you can get
here), which functions as a combination mod installer, mod manager and launcher.
Read more about it
here, but do be aware that the knossos installer linked to there is outdated, only use the one I linked to above.
If you need help with it, please post here or join the
HLP discord