No ads being shown for music/radio app

The music/radio app was fairly lucrative since the user could make $0.122 daily only listening to radio/music daily.
However, it appears that there is a shortage of advertisements for the last few days
Usually only after viewing the ad or watching the video, the user can listen to radio or music.
In the last few days, the users are getting the message, there are no ads available, please try later.
So the users are making very less money listening to radio/music at present.