First, you have to click on the Payments tab from the left side, Click on the Products from your top address bar, and then click on the Add Product button.
Product window is open for you, Add the complete detail of your product and save.
Now Add the product to the package. Click on the White label tab and then click your package on the top bar and select the package where you want to add this product for your customers.
Now click on Add Service button and select the product detail here.
Select the product and add them to the package, and save the settings your process is complete.