Problem Use Api

When using a different domain to use API and fetch data, I receive the following Error:
I need your guidance regarding this problem...
Thank You
my code:
    const url = "";
let headers = new Headers();
headers.append('Access-Control-Allow-Origin', '*');
headers.append('Access-Control-Allow-Credentials', 'true');
headers.append('authority', '');
headers.append("Authorization", `Basic ${auth}`);
headers.append('Content-Type', 'application/json');
headers.append('Accept', 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9');

fetch(url, {
  headers: headers
.then(response => response.json())
  (json) => {
      isLoaded: true,
      products: json.products
  // Note: it's important to handle errors here
  // instead of a catch() block so that we don't swallow
  // exceptions from actual bugs in components.
  (error) => {
      isLoaded: true,

Screen Shot 2021-02-07 at 8.50.39 PM.png

Screen Shot 2021-02-07 at 9.05.46 PM.png

my cs-cart url:

get api by react project in :

Fetch api is done without "Access-Control-Allow-Origin" error.

api get without "Access-Control-Allow-Origin" error...

but "Access-Control-Allow-Origin" error and not fetch api

please help me...