How to embed site cookie in the request header from background js in chrome extension

I have extension for getting data from AWS product page. For example : https://sellercentral.amazon/gp/site-metrics/load-report-JSON.html/ I have to send this request with GET parameters on background.js with headers. In the last time, I have sent this request on inject.js file. And it worked. But it is not working anymore because of new rule (CORS). So I have to sent this request on background.js. When I sent this request, there should be headers with cookies and other values. But I can't set the cookies on request header, so the correct response data is not returning. If you have any experience with those problems and solutions, let me know.

 var myheaders= new Headers({
        'Accept': 'application/json', 
                'Content-Type': 'application/json', 
        "Accept-Encoding" : "gzip, deflate, br",
        "Accept-Language" : "en-US,en;q=0.9",
        "Connection" : "keep-alive",
        "Cookie" : cookieString,
        "Host" : "sellercentral.amazon.com",
        'Referer': 'https://sellercentral.amazon.com/gp/site- 
         metrics/report.html',
        'Sec-Fetch-Mode': 'cors',
        'Sec-Fetch-Site': 'same-origin',
        'X-Requested-With': 'XMLHttpRequest',
});
var fetchOptions = {
    method: "GET",
    credentials: 'include',
    headers :myheaders
}
try {
        let response = await fetch(url,fetchOptions);
        console.log("response", response);
        if (response.status != 200) {
            console.log('Looks like there was a problem. Status Code: ' + 
            response.status);
            return {status: "error",data:""};
        }else{
            return {status: "success",data:response};
  }
} catch (e) {
    console.log('Fetch Error :-S', e);
        return {status: "error",data:""};
}