Official and community resources for the BF-1909 software include:

Standard BF-1909 radios are band-separated. “Extra Quality” software allegedly allows programming of continuous TX from 136-174 MHz and 400-470 MHz in a single unit (ignoring hardware filters). It may also enable “out-of-band” transmission (e.g., 220 MHz or 520 MHz).

A programming cable is required to connect the radio to your computer. Ensure the cable matches your radio model's connector and that your computer has the appropriate interface (usually a serial port or USB).

Push the 2-pin connector firmly into the radio; it often requires a "click" to sync properly.