Here is the answer :
"Thank you for contacting Marketplace Support.
All content obtained from the UE Marketplace is licensed for use under the Epic Content EULA here:
Unfortunately, we are not able to provide legal clarifications for specific use cases. If you are unsure if your use case is allowed under the license above, we recommend reviewing this with your own legal counsel.
Thanks,
Unreal Engine Marketplace"
They could not give me a precise answer to my specific question.
What is your opinion on the Epic Content EULA and my question ?