I\'m using paypal adaptive payments for my website. I have different sellers and different products but the problem is that when a user buy something from my website in the
With Adaptive Payments you will need to use SetPaymentOptions API Operation in order to modify those fields (line item, business name, etc), you can find all the variables here.
You can find an example here: https://github.com/paypal/adaptivepayments-sdk-php/blob/master/samples/SetPaymentOptions.php
Line item works with embedded flow only.
Here is an official reply from PayPal I got today:
You can display line item details for the Embedded flow only. The Embedded flow uses either a lightbox or a minibrowser for the checkout pages. The item details you set with SetPaymentOptions are only displayed to the customer via this Embedded flow.