Create a stage of acceptance and payment of the order.

[sb-github]

Allow users to pay for their food.

When order food user must be signed-in and if he have not enough balance must show pop-up window with advice to check order in credit or buy and pay.
When press pay, send the user to the payment page. can be realized through privat24.

In my orders add table unpaid orders. The same orders just add field to database with checking payment. And button to pay for all unpaid orders.