Joom wants to make sure that the customers get the best offers at a fair price. So, while Joom promotes your products by announcing future discounts to the customers, you won't be able to edit the products you added to the promotion.

To learn more on Joom promotions, please refer to the article Promotions.

Once the promotion status has changed to Preparing, all the promotional products will have the Change Postponed status. That means that all the changes you made to the products will be published only after the promotion ends.

“Change Postponed” status is applied not to all the promotions. If it's applied you'll see the Product changes line in the promo requirements.