CORS error while trying to make http request

[e4d]

Hello,
I'm trying to develop a webpage which shows the state of all of my three Duet-based 3D printers. I made a webpage with a JS script that point to : http://192.168.1.102/rr_status?type=3. I struggle with a CORS error :

Access to XMLHttpRequest at 'http://192.168.1.101/rr_status?type=3' from origin 'http://192.168.1.129' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
jquery.min.js:2 GET http://192.168.1.101/rr_status?type=3 net::ERR_FAILED 200

I've done some research and it always point me to something to do server-side. Since server is Duet here I don't really know how I can go past this.

Here's the JS code reduced to the simplest form which still don't work :

var obj;
url = 'http://192.168.1.101/rr_status?type=3'

let response = await fetch(url);

if (response.ok) { // if HTTP-status is 200-299
     let json = await response.json();
     obj = json;
} else {
     alert("HTTP-Error: " + response.status);
}

I tried to access the page with my browser and I successfuly have the JSON in response. It doesn't work only with the script.
Can someone point me in the right direction ? I didn't found something like this on the forum so I think it can be relevant to others in the future.

[MintyTrebor]

@e4d https://duet3d.dozuki.com/Wiki/M586 might help

I have to add M586 C"*" into my config.g to remove Cors errors when I am debugging/testing a DWC plugin, so it might work for you...

[e4d]

@mintytrebor thank you for your answer, it works great now