Opera Cafe review: Complaining about Opera Cafe and lounge 2255 Emmons ave Brooklyn NY

The Opera cafe restaurant have a 3 % fee when you make a purchase using a credit card. Is this illegal. I ate at restaurant on 7-26-22 paying by Capital one visa credit card ending in 3624 and note that receipt said card fee of 3 % and $ 2:03 was added to receipt. On the receipt it said there will be a 3% card fee when you pay by credit card. We spoke to manager Apo who noted that there is nothing he can do to resolve issue of credit card fee.