Question about hamax Caress

I received the product yesterday. It is problematic. There is no knob to adjust and fix the studs on the luggage rack. There are no assembly instructions. The adapter has already been fitted to the seat and cannot be adjusted, or the adapter has snapped onto the seat. It is possible to adjust the opening of the rear spikes but the adjustment of the rear spikes is obstructed by the footrests. As a result, it doesn't seem possible to tighten these clamps properly on the luggage rack. I can't find any assembly videos for this model. The assembly videos for the adapter do not match either. Please send me a video or at least instructions for this model tomorrow. Or send me the standard model as soon as possible to avoid prolonging this inconvenience and reorganising the transport of children. Thank you very much