Working with the PayPal API and using the Name-Value Pair Interface PHP source codes from SDKs and Downloads: Simplify Integrations with Downloads and SDKs.
My question is similar to "Removing (or prefilling) the address details for PayPal Express Checkout" but I don't want shipping cost/address or anything related about shipping at all.
I keep all shipping details on my system (even sometimes shipping doesn't even apply and there is no charge for it) and I just want user to pay through PayPal without shipping address and shipping cost.
How can I disable shipping part of checkout?
If you're using the newer API, you could also pass NOSHIPPING=1 (not no_shipping)
Further details about all possible parameters to the SetExpressCheckout here:
https://developer.paypal.com/docs/nvp-soap-api/nvp/
Or lookup for Payment experience in new REST API