Issue solved, no more error '20:electronic brake'. Motor is spining. Actually it was not error. It was more like indication that controller is initiating electronic brake which actually is 'variable regen'. If app creators would call it variable regen but not electronic brake than I think I might have clue beforehand.
Waited till Vito and Carrie from QS started their new day. It's 4am now at my place. They told right away that this error due miswiring.
There are two connectors for throttle (which are actually called handlbar on the wires
-One connector for regular throttle (red,black,grey) and
-Another connector for Variable Regen Brake (red,black,brown)
Previuosly I believed that I need to connect connector with red,black,brown wires instead one with red,black,grey.
This '20:electronic brake' is indiaction that controller is initiating variable regen. Instead giving signal to spin motor I was initiating varaible regen braking. It seems so obviuos now but it did not back than; but again, maybe due not consistent naming '20:electronic brake' instead 'xx:variable regen'.
I wonder how practical is second throttle for regen. Unfortuantly I won't find it soon as there is no place to mount it on my scooter unfortunalty but if there were I would try it for sure.