Not able to set Origin in request header in WKWebview

I have an iOS app centred around a WKWebView loading local web assets with loadFileURL. The WKWebView communicates over HTTPS to a backend API. We have made some changes at back end and due to that we need to send some app specific values for Origin of request header. In case my case value is getting replace by some default value as file://. I'm getting CORS issue while loading my application.

Can I change the origin of the WKWebView to xyz to avoid browsers from querying the API?

Not able to set Origin in request header in WKWebview
 
 
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