Hello Cem,
Thank you for your suggestion.
Unfortunately, at the moment, such features cannot be implemented in the Store Manager for OpenCart.
But Store Manager has a feature POS.
You can check the article on how to create POS
https://www.opencartmanager.com/useful-articles/opencart-order-managemement/create-opencart-orders-with-pos-point-of-sale/
Wishing you a great day!