You can download a excel sample template file
here
The input file should have three mandatory columns
1)
Product_name - The name of your product
2)
Price - Price of each product
3)
Currency - Currency in which you want the payment link to be created for
4)
Quantity - Quantity of the Product you want to charge for.
After the mandatory columns, you can add as many columns as you want during in the input file, and they will be retained in the output along with Payment link,
although it will have no impact on how the Payment link is generated. Only this 4 mandatory Columns are used to generate the payment link.