The whole error message is as follows:

Missing or Invalid Field in Promoted Objects: For optimization goal APP_INSTALLS, application_id needs to be valid. Please set it in the Promoted Objects. (#1815437)

What I must say is that my (Flutter) Android app is published to Play Store and is registered to the Facebook developer panel BUT the Certify adherence to allowed usage and all applicable terms and policies. process is not yet complete as I struggle with it for now: the app states is marked as: restricted.

Thus my questions are:

1. Do you think the error occurs because of the restricted status?
2. Does my app MUST embed the Facebook flutter SDK for a campaign to promote it to work?

Thanks for your help.