Billie Eilish London tickets

Hi! Incoming lengthy post but please read in case you can help!!!

So I am from the United States and my parents just surprised my sister and I with floor tickets for Billie Eilish in London this July which they bought using stubhub.uk.co. It says they are not available for mobile download until the day before the concert. I feel bad because my parents were so happy to surprise us and bought these tickets assuming this website is associated with the original StubHub and thought they would be legit. After reading up on threads and hearing pretty negative reviews/scams, is it basically certain our tickets won’t be real/wont be accepted at the O2 Arena? Or is there a good chance we should be fine with these tickets?

If the tickets are real, I read that they can potentially be transferred from stubhub to your AXS or Ticketmaster account. How can I about doing that to make sure they’ll be accepted at the entrance? Do I need to provide that info to the seller completing the transfer or?

Sorry for the lengthy post but since this is our first time ever purchasing tickets for a concert outside of the U.S. we have been stressing about potentially being scammed and want to figure out the best way to go about this. Any helpful information would be appreciated!