I've integrated Adaptive Payments with Preapproval option to charge users periodically a given amount of money. I'd like to now give users an option to change the amount they're paying - looking through the PayPal documentation I can't seem to find any calls regarding modifying an existing Preapproval.
Is it indeed not possible to update a Preapproval, and the only option is to create a new one?
Yeah, you'll have to send the user through some sort of a flow again anyway to update their options, so you could just pull their current setup using PreapprovalDetails, then pre-populate an update form for the user using those details, let them adjust whatever they want to adjust, and then submit a new Preapproval request to create the new agreement based on the new options.