Gift cards are a products like other 'real' products. So everyone can order it and get dedicated gift card. This is why to make module work we must create a gift card product first.
Create gift card product
Go to your catalog > products section and create new product. While you will create it please focus on product type. If product will be virtual - customer will not have to pay for product delivery (if you want to sell digital gift cards it is nonsense to pay for delivery). If you want to sell reedem codes for example on dedicated business cards - create standard product, customer will have to pay for delivery of gift card. Just treat this product as other products. Define its price, personalize descriptions, some images etc.
Many gift cards
You can create as many "gift card" products as you want. For example you can sell gift card products with different values like €25, €50, €100, €500 etc. Value of product (this what customer will pay you) will be a value of gift card that plugin will generate. Once your product will be ready - you can go to the next step where I explain the association process (association between product and engine to generate gift cards with defined settings).