Is it obligatory for me to return the money to the owner of the website that I used to meet girls and engage in forbidden relationships, after I stopped and closed the website?

If someone rents a location for an unlawful purpose, the contract may be terminated, based on Allah’s Almighty words: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression). The landlord is entitled to the rent for the period the tenant benefited from the location, and the remainder should be returned to the tenant.