Recipe says to not drain the beans. Per comments add smoked paprika and the soup is a little runny so maybe thicken with flour.
So I made it and added paprika. Also threw in some chopped courgettes, mushrooms, tomato puree and a tin of green lentils. Was really tasty and serving it with the guacamole made it a bit different. Also had a bowl of natural yoghurt with finely diced cucumber and mint in case the soup was too spicy (it was fine but the yoghurt combo worked well with it). Dry fried a wrap which I spread with grated cheese (chopped spring onions would have been a good addition) and topped with another wrap. Flipped it and when toasty on both sides cut into triangles. Made for an interesting meal.