In the official Google Analytics iOS SDK documentation, this function call will enable Display Features in your app:

id tracker = [[GAI sharedInstance] defaultTracker]; // Enable Advertising Features. 
[tracker set:allowIDFACollection value:@YES]; 

Sadly, this causes an error, as allowIDFACollection is an invalid key. The real way to enable display features is to call this method:

[[GAI sharedInstance].defaultTracker setAllowIDFACollection:YES]; 

Save yourself a few minutes of frustration. Build and be happy.

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