I have the tow package on my 2018 Disco V. Looking to tow a mid sized trailer. The LR tow ball accessory from the dealer is about $400. U Haul offers a tow ball to 2 inch hitch for $24.

Any reason why the standard u haul one isn't appropriate. $400 seems a lot to fit a ball to a tow hitch receiver...

 

I have only used the receiver for the bike rack, but it is std 2". See no reason not to use any standard 2" setup, just check the height, etc. Some people like adding clamps to reduce any noise when towing loads.
The one nice feature of the D5 towing system fitted in the US is that it has both the 4pin and 7pin electrical hookups.

 

$400 for a tow ball??

Uhaul or any other will be fine.