Draw debug of SweepSingleByChannel?

The answer was in the thread I posted, but not in the message that appeared:

These functions are called UKismetSystemLibrary::CapsuleTraceMultiForObjects, UKismetSystemLibrary::SphereTraceSingle etc. There are different combinations. These include the debug and the input and and output matches the blueprint counterpart.

In this example call you also have how to declare an empty actor TArray and how to convert the trace channel type:

UKismetSystemLibrary::SphereTraceMulti(this, CameraComponent->GetComponentLocation(), GetActorLocation(),
Radius, UEngineTypes::ConvertToTraceType(ECC_Visibility), false,
TArray<AActor*>(), EDrawDebugTrace::ForOneFrame, OutHits, true)

Use EDrawDebugTrace::Type | Unreal Engine Documentation to enable or disable the debug trace.