Weeell, let's take a step back here. First of all, I don't understand what you are trying to prove. That when requesting data from some URL some certain reply comes back?
Even if you were to prove that, the API / backend could always change so you can only prove at most that it did return said data in a certain point in time.
You also don't really need to publish that on the blockchain, instead simply send the proof to the people interested in said proof and call it a day.

You're also correct in that proving ownership or knowledge of something can be easily done using Zero-Knowledge Proof algorithms and no secure element is needed for that.