Requesting data from API with XML format

Question

I am not new to programming, but I have some issues with some API requests.

I have the next route (example):

https://test.com/api/products

The return in postman is OK (example):

And my code is (example):

let url = 'https://test.com/api/products';
let username = '1234567890abcdefg';
let password = '';
let headers = new Headers();

headers.set('Authorization', 'Basic ' + base64.encode(username + ":" + password));


async function testAPI(){
    const res = fetch(url, {
        method: 'GET',
        headers: headers,
    }).then(function (resp){
        return resp.text();
    }).then(function(data){
        let parser = new DOMParser(),
        xmlDoc = parser.parseFromString(data, 'text/xml')
        console.log(xmlDoc)
        return (xmlDoc)
    })
}

With my code, I have the next issue: EventSource's response has a MIME type ("application/json") that is not "text/event-stream". Aborting the connection.

As I understand, I have some lack of knowledge about API request returns XML file.

What I trying to do:

I am trying to get data from API request, but API request returns data in XML format. I like to transform XML to JSON after and make next actions.

P.S. How I do this with JSON format (example). I like to do this exactly, but with XML.

async function testAPI(){
 const res = await fetch('https://test.com/api/products')
 const json = await res.json()
 return { apiRawData: json }
}