Here is an example of creating a minute package. Once you have sold this package to a customer, they will have 100 minutes for tanning on their account. The transaction must be done prior to tanning (renting the bed), if you want the minutes to be used.
Then when you go to rent the bed, the minutes for the tan will be automatically deducted from their minutes on account.
You will need to select an item type that has a Pack Type of Minutes. Do not change the Inventory Type on this screen. If it doesn't come in correctly, you did not choose or create the right kind of Item Type.