How do I record advance payments for purchase of goods or commodities such fuel at the filling station to be drawn on reducing balance by using tomcards or coupons.
Read the Guide: https://www.manager.io/guides/7095. This will cover a situation where you pay the filling station in advance.
Coupons are discounts, since they generally have no value of their own. Read this Guide: https://www.manager.io/guides/10530.
Prepaid credit or debit cards are probably best handled as cash accounts. Read this one: https://www.manager.io/guides/9219.
In general, there is a Guide covering almost everything.
Thank you for your help, will take time to read the guides