software creation paypal ebay royal mail

Hi. not sure if im in the right section here but lets see. i sell items on ebay and create the postage thru paypal. Paypal gives me the ability to create postage label from ROYAL MAIL. all the items i sell go royal mail but and they all weigh the same weight. The problem is im unable to create bulk postage and have to process each item sold one at a time. I know i can do this if i use a third party software like linnworks but this will mean creating a royal mail business account or PPI which i do not want to do. all i want to be able to do is create multiple postage labels for the items sold in ebay that are paid with paypal. so in summary create multiple postage labels from paypal for royal mail first class recorded dont want to create a royal mail business account dont want to create a PPI royal mail account I do have a click and drop royal mail account so i either need someone to show me how or create a small software to achieve this. thank you