Be careful when setting up Amazon credit card auto payment, so call “recurring payment” through synchronycredit.com which manages amazon store card and credit card. synchronycredit is bad at the automatic payment so call recurring payment, it doesn’t go into effect right away and in fact they don’t even know when, they say within 1-2 billing cycles.
However there is a way to find out for sure without having to call, chat or contact email writing to them. You can check your statement online or paper, look in the “card holder news and information” it will say so similar to below. Otherwise you will get charge up to $35 late fees because you autopay recurring payment didn’t activate, it’s a waste of time to call contact them to reimburse, if they even will reimburse you or not.