Electrical problem ..!

I have a 200watt solar panel mounted on a Pegasus top on my np30 0 [2016] its hooked up to a solar controller which is connected to the battery in the front of the truck , the accessory feeds my Indel fridge in the tub, is protected by 3 20/30 amp fuses , one of which is switchable and self setting .
Trying to get this approved by the Spanish Authorities , below is what i got back today from the engineer who has prepared the report .

After consulting several certifying companies, there is no other
option than to mount an electrical circuit separator relay that cuts
the voltage when starting the engine, this is required due to the lack
of accessories with electromagnetic compatibility certification
(manufactured for vehicles). As for the rest, no problem.

Once the separator relay is assembled and the photos have been taken
to present them,. I am very sorry for theinconvenience, until now the switch was enough but they require the
relay.

So any



one any idea whats required as all i can find is switching relays for a dual battery set up which is not what i have or need .