AP finding out date of purchase

[Max1987]

Good Morning guys,

My sister asked me to buy a new AP for her and so I did thru Chrono24. Watch came a bit scratched despite the 500+ positive reviews of the seller.
We decided to keep the watch anyway, but now I'm questioning if the year of the watch (2022) they stated on ads it's real or not. I'm worried it might be an older series.
On the new Warranty card no date is shown and I really don't know how to find it out. The only way to find out the date of purchase seems to get registered and extend the warranty on AP website, correct ?
My question is, since I want to make sure about the year before handing the watch to my sis, can I first register it on my name and later on my sis register the watch again on her name? Or it can be done only one time ? I'm a bit confused about all this as it's our first AP. If someone can clarify how everything works I will be forever grateful.

Personal note, i wish there was a simplest way to find out the date of Original purchase. Why on earth they won't state it on the documents ?😪

Thanks lot guys and wish you a great day ✌️