Use the other key fob.. or push in on the button in the middle at the endof the trunk lid edge.

 

What are you talking about?

Push in on this..

 

Dealer time then, is all I can tell you ..If your rear seat backs come out, there is a pull release in the trunk to open it..

 

Ive replied in your duplicated post
https://www.jaguarforums.com/m_65317/tm.htm
PS My rear seats are the non folding kind.You can remove them from inside the car (base lifts up and backrest unbolts (2 torx srews IIR) once you pop the locks.The alarm will sound for a while when you open the doors so leave the doors open as every time you close/reopen a door the alarm willl start again until you access the boot and use the fob to turn it off.
As an option instead of removing the rear seats you can (when youre inside the "cabin") short out somepins as it describes how to do in the reply linking to the .co.uk link on your duplicate thread
Good luck