Use iPhone and starting warranty from buy product

hlo sir madam ,

I have purchased my iPhone 11 ,128gb black from Amazon on 17/4/21 . But it and not covered proper and red tape sealed from 2 side . But I have checks my warranty online from serial no and it has start the warranty but I have not open the box and the warranty expires on 19 October 2021 . But Ihave recieved today 21/4/21 from Amazon delivery agent