doesn't get the keys :/

main.py

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.graphics import Color, Ellipse, Line
from kivy.uix.boxlayout import BoxLayout
from kivy.core.window import Window
from kivy.interactive import InteractiveLauncher

import random

framePoints = [150, 250, 750, 250, 750, 600, 150, 600, 150, 250]
CIRCLEPOSITIONS = ([200,300],[350,300],[500,300],[650,300],[200,400],[350,400],[500,400],[650,400],[200,500],[350,500],[500,500],[650,500])
CIRCLESIZE = 80

RED = (0.3,0.3,0.3)
BLUE = (.6, .8, .6)
WHITE = (1,1,1)

NTRIALS = 12

itemGroups = {'YN': [[['T','TICK'],['T','POCK'],['Z','TICK'],['Z','POCK'],['M','TICK'],['M','POCK']],[['T','TICK'],['T','POCK'],['Z','TICK'],['Z','POCK'],['M','TICK'],['M','POCK']]]}


class Circles:

	def __init__(self, posx, posy, color):
			self.x = posx
			self.y = posy
			self.col = color
			
			
class Configuration:

	def __init__(self, nred = 6, nblue = 6):
			self.nred = nred
			self.nblue = nblue
			self.circles = []
			self.setupConf()
						
	def setupConf(self):
	
			circlePosz = list(CIRCLEPOSITIONS)
			
			for i in range(0,self.nred):
				coord = circlePosz.pop(0)
				self.circles.append(Circles(coord[0],coord[1],RED))
			
			for i in range(0,self.nblue):
				coord = circlePosz.pop(0)
				self.circles.append(Circles(coord[0],coord[1],BLUE))

class Trials:
		
		def __init__(self):
					self.setup = None
					self.question = None 
					self.ans = None 
					self.time = None 

		def evaluate (self, answer):
				return True
				
				

class Session:

		def __init__(self, tyype, number):
					self.tyype = tyype
					self.number = number
					self.trials = []
					self.makeSession()
							
		def makeSession(self):
			
					for group in itemGroups[self.tyype]:
					
							random.shuffle(group)
							for tr in group:
									
									if tr[0] == 'T': nred = 12
									if tr[0] == 'Z': nred = 0
									if tr[0] == 'M': nred = random.randint(4,8)
									
									thisTrial = Trials()
									thisTrial.setup = Configuration(nred,12-nred)
									thisTrial.question = tr[1]
									self.trials.append(thisTrial)				
							
					
#					if self.tyype == 'YN':
					
#					if self.tyype == 'COMPARISON':
					
					


class DisplayWidget(Widget):
	
    trialDisplayed = 0
  			
    def __init__(self, frame, setup, **kwargs):
        super(DisplayWidget, self).__init__(**kwargs)
#        Window.clearcolor = (0.1, 0.1, 0.1, 1.)


        with self.canvas:
        
                Color(*WHITE)
                Line(points=frame, width=2.5)           
                                                    
                for circle in setup.circles:            
                    Color(*circle.col)
                    d = CIRCLESIZE
                    Ellipse(pos=(circle.x , circle.y), size=(d, d))

	
  
class TiktokApp(App):

    def build(self):		
		
        trialDisplayed = 0
        session = Session('YN',1)
        layout = BoxLayout(orientation='vertical')
        display = DisplayWidget(framePoints, session.trials[trialDisplayed].setup)
        text = Label(text=session.trials[trialDisplayed].question + ' cercles sont rouges')
        layout.add_widget(display)
        layout.add_widget(text)
                      
        return layout

    def build_config(self, config):
        config.setdefaults('graphics', {
            'width': '1280',
            'height': '1024'
        })

##### why doesn't it work? :)
        
    def _on_keyboard_down(self, keycode):
        
                if keycode[1] in ['m','y']: trialDisplayed += 1



if __name__ == '__main__':
    TiktokApp().run()