AppFlyer has two types of integrations; Push API method and Integrated Partners method.
For Integrated Partners method, any AppsFlyer user can use this method, however, with the current set up, it is restricted to a single campaign group per application.
What this means is that, if you have more than one campaign group for your application (per app), you will only be able to integrate only one of them.
If you are not able to see all of your campaign groups on Ads Manager page on SearchAds.com after you have successfully integrated your app, it is due to the method between AppsFlyer and SearchAds.com
As for the Push API, this method is only available for users with AppsFlyer Premium accounts. If you are an AppsFlyer Premium user, please contact us.