How can I have images in gallery (shop) retain original aspect ratio?

Hello! I'd like have the product images in my shop-gallery retain their original aspect ratio, but share the same height. What I don't like is the weird crop that happens for different art pieces. How can that be done? I'm new to adding custom CSS in squarespace. Thanks!

Do you have link to this page? Or you try this to Website Tools > Custom CSS

img.grid-item-image {
    object-fit: contain !important;
}