I tried to change headers using setRequestHeader and updateRequestHeader but headers didn’t change when prefetching. Is there any way to change them?
Can you provide your router code for this route? Prefetching responses are served from the edge cache so perhaps what you are seeing is a cached response with no change.
How are you viewing the headers? Using chrome debugger? Keep in mind that setRequestHeader and updateRequestHeader only affect the headers send from the XDN to the origin, not those sent from the browser.