Problem with autocomplete for certain functions/variables

[chris-gong]

I was watching this video at timestamps 6:22 and 7:12, and if I try typing out either UNiagaraSystem* system or UNiagaraFunctionLibrary::SpawnSystemAtLocation, I notice that there's no autocomplete as I type these out nor is there an auto include for the header files for these (#include NiagaraSystem.h or #include NiagaraFunctionLibrary.h).

Even when I type out SpawnActor, the autocomplete isn't smart enough to figure that one out or pick up that it should be prepended with GetWorld()->SpawnActor(...)

Do I have to disable Intellisense in the settings for Microsoft's c/c++ extension? Do I need Unreal built from source? Lastly, I made sure that I'm using the correct Windows SDK, msvc toolchain, and llvm versions with the correct clangd path.