If you have your inventory management feature enabled, you might encounter a pop-up message on the register once you try to create a transaction. This pop-up message only appears when you have not set your sales warehouse on the general settings.
Make sure you have added your sales warehouse and assigned your sales items to the warehouse. Learn more about adding warehouse here: https://help.kahero.co/adding-warehouse/
You will encounter this message on the register when clicking "Payment".
To fix this, go to the "Navigation Menu". Scroll to "Settings" then click "General Settings".
Scroll down to find the "Sales Warehouse" section. Select your "Sales Warehouse" and "Online Store Warehouse". Click "Save".
After setting your sales warehouse on the general settings, you will now be able to proceed to the payment screen on the register.