Cheerson cx20 open source apm version


newbee needing some advice bought a second hand cx20 all good goes in all directions as advertised .as this is my first drone a steep learning curve needed so decided to plug into a usb with various planner software to see what can be adjusted ,unfortunately after many attempts its not going to connect so took it apart connected directly to apm usb still no joy so followed a few vids all saying reset pressing the button on apm however there don’t seem to be one so I geuss I have a old edition can this be just swapped over to a newer version or am I stuck with what ive got
cheers tim