If you wish to enable the ecommerce functionality, login to the admin area and go to the config settings. 

Change general.ecommerce.enabled to "checked".

The jobboard.ecommerce.basecountry setting should be the two-letter ISO code of the country in which your job board is based. This is used to determine if tax should be applied to orders, based on the location of the user making the purchase.

jobboard.ecommerce.basecurrency should be set to the three-letter ISO currency code, for example USD, EUR, GBP, JPY, etc. This is used to ensure pricing is clear to users, and also passed through to the payment system so the correct amount is billed.

jobboard.ecommerce.credits.price is the price in currency units (of the above currency) for one credit, excluding tax.

jobboard.ecommerce.credits.taxrate is the prevailing sales tax or VAT rate applied to orders in the base country specified above. Typically this is only charged to orders from users in the same jurisdiction.

jobboard.ecommerce.vatnumber is the tax ID or VAT number of the company operating the job board. In the case of EU countries, ensure the correct two-letter prefix is present.