Unreal Engine 4 watermark and donations

I have qestion about adding my watermark to image, when I always design a new level in Unreal Engine 4 ( Using Epic Games Assets ) at the end of the process I take screenshoot with my final work and I add my logo ( watermark ) to protect my work against theft.
Do I have to write under Photos, who it the original Author of the Assets…?
I have one more qestion about donations, Can I add donations options under the photo ( If someone likes my work and appreciates that he can donate me and support me )
I do not have any benefits from Level Design ( All Projects all do after work when I come home ).

I’m not sure I understand your question, but if you take a still image of your UE4 work, we don’t require you to identify an author.

No problem on our end if you want to include a watermark, and we don’t require it say anything particular. If you wanted to use an Epic logo like the image you posted, you need a trademark license.

As for donations, donations are generally not royalty bearing unless the person donating gets some kind of in-game access or benefit.

Something like that, under this photo I must write who create the original assets and what about donations…?

I inlcude a image below :), it often happens that people steal pictures with projects and sign as their own.