Can I use UE assets for mobile apps advertising?

Can I use assets from the Unreal Engine store to advertise existing games?
I work as a freelancer and I am ordered to make a commercial: put a character
from the game in an environment from the Unreal Engine store.
I didn’t find any information in the license on the use of Unreal Engine
materials for advertising, and my lawyer couldn’t tell me either.

Can you help me and clarify this point? I really don’t want to do anything
illegal.

Marketplace assets are intended for use in your commercial projects. If you’re only using them in non-interactive linear media (e.g., rendered videos or images), then you won’t owe any fees to Epic for that use.