From version 180, we supported the Wallet feature for User. See the screenshot below:
1. For Customer
After register an account, the customer can see the "Credit" field in the Profile menu. From starting, that balance is 0.
To buy Credit, you can press to "Buy Credit" to buy the credit for your balance:
Select the amount you want to buy, and do checkout:
The Email confirm will be sent to your address, remember to pay attention to check.
2. For Admin
Access to the Report > Credit Purchase Report to see the report:
Mark the "Completed" status to allow customer use the credit that they asked