Woocommerce POS with Click&Collect

Hi there,
I’m looking for a POS system that can do the following:
– Customer orders in WooCommerce shop and chooses “Pick up from store”
– Customer does NOT pay via Woocommerce/online, but chooses “pay at store”
– Customer comes to store, picks up his goods and wants to pay
— POS system lets me choose his Woocommerce order and assign his payment to it
— Payment is done via Zettle (!)

– Additional requirements
— Customer adds further goods to his order at store (IRL not online)
— POS system lets me add those goods to his existing Woocommerce order
— Payment is done via Zettle and has also to be asigned to this order

Does anybody have any idea of a possible solution?
Many thanks, best regards and happy easter
Muhackl