uvv99

Победа! Нужно было добавить разрешение на доступ к камере и интернету в buildozer.spec

Еле разобрались, нашли выход:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.core.window import Window
from kivy.clock import Clock
from requests import get, post
from kivy.uix.camera import Camera

Window.size = (360, 480)
Window.clearcolor = (0, .17, .55, 1)


notice_list = []
department = 'kmd'


Builder.load_string("""
<MenuScreen>:
    BoxLayout:
        orientation: 'vertical'
        padding: 5, 10
        spacing: 10

        Button:
            text: 'УВЕДОМЛЕНИЯ'
            background_color: 0, .12, .52, 1
        Button:
            text: 'ЗАКАЗЫ В РАБОТЕ'
            background_color: 0, .12, .52, 1
        Button:
            text: 'АРХИВ ЗАКАЗОВ'
            background_color: 0, .12, .52, 1
        Button:
            text: 'СКАНИРОВАНИЕ QR'
            background_color: 0, .12, .52, 1
            on_press: root.manager.current = 'settings'

<ScanScreen>:
    BoxLayout:
    #:import ZBarCam kivy_garden.zbarcam.ZBarCam
        orientation: 'vertical'
        padding: 5, 10
        spacing: 10

        ZBarCam:
            id: qrcodecam
        Label:
            size_hint: None, None
            size: self.texture_size[0], 50
            text: ' , '.join([str(symbol.data) for symbol in qrcodecam.symbols])

        Button:
            text: 'РАБОТА НАЧАТА'
            background_color: 0, .12, .52, 1
            on_press: app.start()
        Button:
            text: 'РАБОТА ПРИОСТАНОВЛЕНА'
            background_color: 0, .12, .52, 1
        Button:
            text: 'РАБОТА ЗАКОНЧЕНА'
            background_color: 0, .12, .52, 1
            on_press: root.manager.current = 'menu'
""")

class MenuScreen(Screen):
    pass

class ScanScreen(Screen):
    pass


def get_notice(_):
    for i in get(f'http://127.0.0.1:8000/api/notice/{department}').text.split(','):
        if i != '':
            notice_list.append(i)


class MainApp(App):
    def build(self):
        sm = ScreenManager()
        sm.add_widget(MenuScreen(name='menu'))
        sm.add_widget(ScanScreen(name='settings'))
        return sm

    def start(self):
        r = get(f'http://127.0.0.1:8000/api/give_csrf')
        csrf = r.text.split('=')[-1][1:-2]
        cookies = r.cookies.get_dict()

        post(f'http://127.0.0.1:8000/api/qr_start/{department}',
              data = {'id': notice_list, 'csrfmiddlewaretoken': csrf},
              cookies = cookies)


if __name__=='__main__':
    Clock.schedule_interval(get_notice, 3)

    MainApp().run()