What is the ruling on working and earning profit from a website that provides products to merchants, where we undertake the marketing and selling and determine the profit margin, while the website handles storage, shipping, money collection, and cash on delivery? Is this considered dropshipping?

What is known as dropshipping is permissible if it is conducted in the form of Murabaha (cost-plus financing) or agency for a fee. It is permissible for a website to sell a described item with deferred payment, or to sell a described but unspecified item with the full price paid at the time of the contract (Bay' al-Salam - forward sale). It is permissible for you to act as an agent for the website for a fixed commission or a percentage. It is permissible to agree on delaying the receipt of the commission, or on it not being due if the item is returned, based on the Prophet's saying (peace be upon him): "Muslims are bound by their conditions." If the contract is annulled for a legitimate reason, such as a defect, the broker is not entitled to a fee according to the Maliki and Hanbali schools. However, if it is annulled without reason, but rather by mutual rescission (Iqalah), his fee is not forfeited. This is based on you being an agent, not a buyer. It is permissible for the website to set a price, and you can add to it, with the excess amount being yours.