i can’t find the main image option in E-commerce products
if you have enabled variants for a product, the main image field does not appear, and instead the product images are managed within your variants’ details - each variant is a separate product and has its own product fields you can set.
The main image, more images, SKU, price, compare-at price, and measurement values set on the main product are inherited by all variants.
You can manually update and replace any inherited values by clicking the variant or the setting icon that appears when you hover over it.