Video as proof

Hi, I would like to know, is it possible to have my video footage certified for a case of a missing package? My Ring doorbell captured a FedEX truck pulling up to our house but the driver never exited the truck. He drove away and now FedEX claims delivery. FedEX denied a claim saying it was delivered. How can I send them or show the footage where they can't claim I changed or deleted any part? The reason I bring this up is that the camera stops at 30 seconds. It didn't record again until 90 seconds later as he drives away. He never approached the house but someone can think I deleted the video between him pulling up and driving away. Can I get Ring to issue a statement that none of my videos have been deleted for the day in question?