In any case, I will leave something here to warn others that it is derece necessarily a sıkıntı in their codes. I am placing an e-commerce system with Laravel and Iyzico, but I am getting an invalid signature error, I don't know how to solve this, I have tried all https://graph.org/2-Dakika-Kural-için-garanti-link-ile-ödeme-alma-07-18