can we choose assignment of midi channel in Musescore2

Can we change the assignment of the midi channel in musescore 2?

If I use a piano by example the two staff ( key G and F) in a midi file export, that two staffs are mixed on the same channel, I have not find where we can change the midi channel in two staff connected.
So if I want to channel I must declare two keyboard in musescore and delete in the first the key F and in the second the G key.
So the channel in midi-export is for the G key is 1, and for the F key is 2.
Can we change the assignment of the channel by example 3 and 4?

Is it possible to change a midi channel independently in two staff connected?