Smartlook Unreal Engine 4 SDK uses UE4's built in Analytics APIs. Because of this, some APIs available on Smartlook SDKs for other platforms are not available on UE4 SDK. You can learn more about UE4 Analytics APIs here:
UE4 Blueprint Analytics API Reference
UE4 C++ Analytics API Reference
Custom event
Unreal SDK does not track any events automatically like other SDKs. It is needed to use Custom Events.
Blueprint:

#include "Runtime/Analytics/Analytics/Public/Analytics.h"
#include "Runtime/Analytics/Analytics/Public/Interfaces/IAnalyticsProvider.h"
FAnalytics::Get().GetDefaultConfiguredProvider()->RecordEvent(TEXT("Custom Event Name"));
Additional custom event APIs
Blueprint:
Record Event with Attributes
Record Error
Record Error with Attributes
Record Currency Purchase (with Attributes)
Record Currency Given (with Attributes)
Record Item Purchase(with Attributes)
Record Progress (with Attributes)
C++:
Record Event with Attributes
Record Error
Record Error with Attributes
Record Currency Purchase (with Attributes)
Record Currency Given (with Attributes)
Record Item Purchase
Record Progress (with Attributes)
Navigation event
Screen/navigation transitions can be manually tracked by using Custom Events.