What is the legitimate legal way to sell goods I do not own by displaying them in an Instagram account, with a request for an upfront transfer of the amount to secure the right, and is it permissible to combine the commission with the original price if buyers complain about it being added separately?

Displaying goods to a potential buyer before possessing them is permissible. However, it is not permissible to conclude a sales contract for specific goods before possessing them, due to the Prophet's (peace be upon him) prohibition of selling what one does not own and profiting from what one does not guarantee. He said: "It is not permissible to combine a loan and a sale, nor two conditions in a sale, nor profit from what has not been guaranteed, nor sell what you do not possess."

Among the legitimate ways out are: 1. Agreeing with the buyer on a commodity with specific characteristics to be delivered at a specified time for a price paid in full at the contract session, which is a salam contract. 2. Entering into an agency contract with the customer for a fee to provide the commodity in exchange for a known commission, or agreeing to provide the commodity for a certain price, and whatever exceeds that amount goes to the agent.