How to add custom attributes to the trace dynamically with xhr request instrumentation

[SunilManthenaG01]

I am using XMLHttpRequestInstrumentation for tracing. I was able to see the traces but I am looking to add some custom header which the xhr request has into the trace. I am trying something like below but i was unable to access the request object from here.

new XMLHttpRequestInstrumentation({
clearTimingResources: true,
ignoreUrls: config.ignoredUrls,
propagateTraceHeaderCorsUrls: config.propagateTraceHeaderCorsUrls,
applyCustomAttributesOnSpan: (span: Span, xhr: XMLHttpRequest) => {
// how to get the request header objects from here.
// span.setAttribute('app-user-id', xhr.getResponseHeader('app-user-id'));
}
}),

[hemendpatel]

@SunilManthenaG01
are you able to add the custom header?

[SunilManthenaG01]

No, I am still unable to get the request object in the applyCustomAttributesOnSpan callback.