Can i use an asset in a place other than unity?

Per example: I want to make my game official website, can I use an texture I downloaded/bought from asset store in the site?
If I can, what i should know?(Can I place ads In the site or not?)
If I can’t, why?
-Important notice: the assets or the textures aren’t going to be sold or downloadable at any moment in the website, I’m going to combine some textures and use them as background, buttons etc.

I suggest you read the EULA:

It is emphasized that the END-USERS shall not be entitled to distribute or transfer in any way (including, without, limitation by way of sublicense) the Assets in any other way than as integrated components of electronic games and interactive media.