WARNING: This page is about a different car, the 2023 Jaguar F-Pace and 2022 Jaguar F-Pace. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC
JLR-303-1649 Coolant expansion tank drain cap
Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC
JLR-303-1720 Cooling System Pressure Tester Adaptor