This is software programmable.
Many of these chinese radios have dual modes.
One mode is "proffecional" mode where almost noting is programmable on the front panel.
The other mode is a "HAM" mode that lets you program almost everything.
The change between the two modes is normally done in the CPS (config software)
Check what cables came with your radio if your lucky it came with the prog.cable.
The software can can be downloaded on
http://www.qx-tele.com/If you dont have the cable you can install the CPS and see if you find something about profecional, ham, VFO mode.
If you see the review on the mikolor website you will see that on the first firmware you wont be able to change the tone.
https://www.miklor.com/COM/Review_AT779.php