Carrot2 returning Either dcs.source or a non-empty document list in dcs.c2stream must be provided

I am hitting carrot2s api with:

const xml = 
`<?xml version="1.0" encoding="UTF-8"?>
<searchresult>
<query>bob</query>
    <document id="https://api.cognitive.microsoft.com/api/v7/#WebPages.0">
        <title>Bob O's Family Fun Center | El Paso, TX</title>
        <url>http://www.bing.com/cr?IG=29AD4AB87B7B438D8F2AA5967E17967DCID=24C5C22679EF67D1293BCE6078F66638rd=1h=AaGhCeGCFZPjz86DB6AZMIlM8b3VlbHiXWyUPsmFL_k=1r=http%3a%2f%2fbobosfun.com%2fp=DevEx.LB.1,5071.1</url>
        <snippet>Bob-O’s is El Paso’s Premier Family Fun Center. Located on the Westside off Sunland Park Drive, Bob-O’s offers a variety of entertainment for the entire family.</snippet>
    </document>
</searchresult>`

    fetch(`carrot2server/dcs/rest`, {
        method: 'POST',
        body: {
            'dcs.c2stream': xml,
            'results': 100,
            'dcs.algorithm': 'lingo',
            'dcs.output.format': 'JSON'
        }
    })
    .then(function(response) {
    response.text().then(function(text) {
        console.log(text);
    })
}).catch(function(err) {
  console.log(err)
});

If I run the same request in postman I get the expected results.

The error that I am receiving is:

HTTP Status 400 – Bad Request

Either dcs.source or a non-empty document list in dcs.c2stream must be provided

The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).

This was fixed by setting the correct encodeURIComponent and adding the content type: application/x-www-form-urlencoded

const params = {
        'dcs.c2stream': xml,
        'results': 100,
        'dcs.algorithm': 'lingo',
        'dcs.output.format': 'JSON'
}

const searchParams = Object.keys(params).map((key) => {
    return encodeURIComponent(key) + '=' + encodeURIComponent(params[key]);
}).join('&');

fetch('carrot2server/dcs/rest', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    body: searchParams
})
.then(function(response) {
    response.text().then(function(text) {
        console.log(text);
    })
}).catch(function(err) {
  console.log(err)
});