From the thread you linked to:
“The TG44 can be used as a standalone generator. There is an application called TGStandalone in the Spike application installation directory which allows you to set the frequency and amplitude of the generator.”
You can also set the TG frequency and amplitude using a TG standalone API, available on request. There are no modulation capabilities, just a CW. The TG output has a lot of harmonics, so a low pass filter should be used if you use it over the air, and you should make sure to adhere to any regulations regarding over the air RF transmissions.