To setup Top Header Options for this theme, please go to Appearance->Customize->Theme Options->Product Single Page Options:
Sticky Add To Cart: This option allows you to show/hide sticky add to cart on product single page.
Sticky add to cart position: This option allows you to change the sticky add to cart position ( top/bottom). This option works only if sticky add to cart option enabled.
Disable Related Products at Product Detail Page: This option allows you to show/hide related product on product single page ( product detail page).
Enable Image Zoom at Product Detail Page: This option allows you to show/hide zooming feature on product single page product images.