How to upload a image in a custom field

Hello,

In order to be sure to understand your needs, can you :
- Explain what kinds of Custom field you have in mind (product, item, order etc...) ? Or where you want have this image, which HikaShop page (listing, product page, checkout etc...) ?
- Details your picture's aim ? It's just for display, select a variant ? Or else...
- If your needs fit it, use some screenshot with annotations will be a good way to better follow you.
Awaiting news from you.

Regards