Hello,
Sorry for the misunderstanding. I know there is an option in the Single product to display extra content.
The confusion was in your word Grid that’s why I replied.
If you want to display the extra content in boxes then try adding the following Custom CSS in the Custom CSS for Desktop area under Theme Settings >> Custom CSS.
.product-extra-content {
width: 100%;
padding-right: 15px;
padding-left: 15px;
margin-right: auto;
margin-left: auto;
max-width: 1222px;
}
Best Regards