ExampleApp does not work #6

I cloned the repository and ran the ExampleApp.
I added user id and app key from the official sample iOS Demo Application 6.7.8:
IronSourceRewardedVideo.initializeRewardedVideo("437ae1ad", "demoapp")

However, it does not work:

I tried to change user id and app key to mine, but it didn't affect my work.

Can you advise anything?