To make changes, go to "Collections" and find the artwork you want to modify under "Offers" Click on the trash bin icon located at the back, and you can delete the pricing and quantity settings.
To set the price and available quantity for the artwork you want to sell, enter the artwork and click on "Sell"
1. If your "Sell" button is greyed out, meaning you do not hold enough amount to sell (<1). Please check if you have all of them on sale (or you do not own any), and tap on the "trash bin" and take back your offers before making any changes.
2. Changing quantity does not mean changing "issuance number of the copies". Number of copies could only be decided during the first upload process, and couldn't be modified once the creation is published.