In principle, you can also connect the washing tower with a "cheaper" connection set (e.g.:
https://www.galaxus.ch/de/s2/product/samsung-skk-df-tumbler-zubehoer-3495318). You can find the suitable connection set on the product page of the tumbler.
I would not place the tumbler on top of the washing machine without a connection set, as the tumbler could fall off when the washing machine is spinning, for example.