Cancel subscription

I started a trial subscription for Adobe Stock on January 21, but I haven’t used it at all and realized that it’s not useful for me. However, when I tried to cancel, I was asked to pay an early termination fee. Why do I have to pay a cancellation fee during the trial period? Isn’t this period meant for trying the service? I want to cancel without paying a fee since I haven’t used the product at all. Can you help me?