free assets in a complete game?

So I have a question that I couldn’t find an answer to
Can I use free assets that I have downloaded with the engine itself
use in the final game or do I have to make them myself?

I am pretty sure that everything that you can download via the EPIC-Launcher (in the UE4-Tab) can be used freely in commercial and non-commercial products.

Source: Regarding free content and usage in your own game - AnswerHub - Unreal Engine Forums

Yep, using them in my project too. But don’t use any other free models/assets from outside the launcher unless your absolutely sure they are free for commercial/non commercial use.