Hello, welcome to the Make Community!
Can you please take a screenshot of the data you get in your webhook module?
As well as some of the rows you want to update, the way you correlate data from the rows and from the item received in the webhook.
And finally, the calculation you do to deduce the value?
I think you won’t need an iterator, and that you’ll be able to use Functions to extract the relevant data that you deduce to each row… but I’m not sure until I get more details from you 