Is it forbidden to work for an online shopping website that allows the display of alcoholic beverages, if my work is limited to helping merchants display their products?

It is permissible to work on websites whose primary activity is lawful, even if they include some forbidden activities, as long as the worker is not involved with the forbidden activities. Based on this, it is not forbidden for you to work on the website, provided that you do not work in matters related to promoting or selling forbidden things.