when you create a new brand you can directly go to that particular brand profile page
there you can found that upload cover image button.
- click on it and browse image and select
- image gets uploaded in cover area
- reposition uploaded image (if you want)
- click save button
If you want to change cover
- click on update cover button
- from there you can newly upload cover image by choosing change cover option
- you can edit that particular cover by click edit cover -> reposition image ->click on save
- you can delete image by click delete cover