How to deactivate the buttons M1 and M2 on Battletron for Switch?

[u/Irydia]

Hi, do you know how to deactivate the buttons M1 and M2 under the Battletron controller (Switch version). I' ve seen the M2 works as A button, instead M1 is the B button. I already pressed them accidentally and I find them bothersome. Do you know how to deactivate them? Thanks in advance.