Go to the bundle editor, then open the Offers tab.
Expand the relevant offer by clicking the small arrow.
Just below the title, click Add custom image.
→ A window will open where you can upload an image in PNG / JPG / JPEG / GIF format.
Once the image is added, you can:
Replace it by clicking Change image
Delete it by clicking the 🗑️ icon
Revert to the Shopify product image by enabling Use product image on offer
→ This automatically removes the custom image you added.
If you encounter any issues when uploading or displaying the image, contact MoonBundles support.