kivmob doesn't show ads in android app python kivy

I try to add ads in my app. I added in my buildozer.spec:

android.permissions = INTERNET, ACCESS_NETWORK_STATE
requirements = python3,kivy, jnius, kivmob
android.api = 28
android.minapi = 21
android.sdk = 24
android.ndk = 19b
android.gradle_dependencies = 'com.google.firebase:firebase-ads:10.2.0'
p4a.branch = master
android.meta_data = com.google.android.gms.ads.APPLICATION_ID=#here id of my app

I have code:

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivmob import KivMob
class TestApp(App):
    def build(self):
        try:
            fl = FloatLayout()
            self.ads = KivMob('')#here my app
            self.ads.add_test_device(here my id)
            self.ads.new_banner('', top_pos=True)#here my banner
            self.ads.request_banner()
            self.ads.show_banner()
        except Exception as error:
            fl.add_widget(Label(text=str(error), font_size=(30)))
        return fl
    def on_resume(self):
        self.ads.request_banner()

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

when I start this app, I see black screen and nothing else. I expected banner. How to fix it? I hope you help me

UPDATE: if I use TestIds.APP and TestIds.BANNER it works and shows ad. Why does it happen? How to use real ad banner?

Solution

So firstly add android in requirements in buildozer.spec. android.api = 28

Yes using TestIds provide ads to be displayed on any device because they are sample ads by google.

But when you are using your own ad units you create from admob account. You have to provide your test device id in your code in order to recognise google that you are testing your own ads.

Use self.ads.add_test_device(YOUR_DEVICE_ID) in your build method.

And where did you get your device ID Well you have to find your device id in logcat output.

Hope it helps.