On previous cars, Daihatsu Fourtrack, Audi A6, Land Rover Discovery Sport, all had tow bar mounted cycle racks. (I've been towing caravans and carrying bikes for over 35 years!!). The Tarraco has a retractable tow bar and no back plate, so there is no tow bar mounted cycle rack that can be used.
When researching a rear mounted cycle rack, there are a number of racks that will take 45kgs including Thule. The one I have bought, and is in the photo, is an Italian make called Peruzzo. They advertise it as specifically for eBikes because the wheel trays are further apart than for normal bikes and can carry up to 45 kgs. You Tube has a good video of the rack being used for eBikes.