Upload custom images could be very useful for developer reasons, to add an image to your custom files.
The first step to upload an image is going to the custom image section and create a name for the image.
After that must upload the image you image you want.
And click on update.
Once uploaded your image you need to rebuild your website. Learn how to do it here.
Then you can access to your image in the next url: https://yourtemporaldomain.ordering.co/img/custom/your_image_name
Use this URL as the source of your image in your code.
In the V4 version, You must use an URL like this: "https://www.yourdomain.com/templates/web/img/custom/custom_image.png"
Glad we can help
Have a nice ordering
Regards, Pol Zepeda