How to adopt FormRequest to API JSON request?

How to adopt FormRequest to API JSON request? Now it looks as:

class CreateOrder extends FormRequest
{

 // Validation rules
}

And using:

public function store(CreateOrder $request)
{

 dd(Request::get('DeliveryDate'));
 dd($request->all()); // Or
}

When I send data to this endpoint, Laravel instead showing incoming data $request, does redirect.

via Chebli Mohamed