Hello,
1/ This element automatically takes images that you uploaded for your categories in Dashboard > Products > Categories > Thumbnail.
If you want to get the result like on the demo, but do not want to prepare your images, custom CSS code can be used for the element, for example:
.category-grid.slide-item {
background-color: grey;
border-radius: 10px;
}
but in your case images have white background, so the result isn’t the best – https://prnt.sc/KtdGqTYiGvFp
Just border can be added via settings of this element – https://prnt.sc/tFdIwumVNfdZ
Kind Regards,
8theme team