Conditional Response when API error

I want to be able to run a conditional response when an API returns an error.

The specific situation I’m dealing with is: I’m using Blockspring to connect to Amazon’s Product API to get the new price of an item. When that returns an error, though, I want to use that same API to get the list price of an item, but I can’t figure out how to get the “When” condition to recognize that the API returns an error. Here is a screenshot of the error.
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