It's called an .sc4 file but I don't, unfortunately, know enough about it to be able to give a detailed explanation. But the .sc4 file allows modification of some aspects of the radio's behavior, including going out of band.
But, there's never any assurance that an appropriate .sc4 file is enough for taking a radio out of band. There's only so much wiggle room for the VCOs to operate outside their designed band limits and at some point you encounter a loss of receive sensitivity and transmit power as well.
Some radios work better out of band than others of the same type.
I will leave the explanation of the details of the .sc4 file to someone who knows about it better than I do.