Issue with Santander Bank PIN?

Hi everyone, I’m not sure if this is the right community to post, but I just received my first credit card from Santander and I thought it would be wise to create a PIN number just like how a debit card is. I utilized the Mobile Banking app and tried to create a PIN but when I clicked Done it popped up saying “This card does not belong to user” and I couldn’t create one. Does anyone know what the issue could be? Do credit cards not have PIN numbers?