add below line of code in fetch
export function getData(endpoint = '/', request = {}) {
let url = endpoint;
let req = Object.assign(
{
headers: {
Accept: 'application/json',
'Content-Type': 'application/json',
'Access-Control-Allow-Origin': '*',
},
},
request
);
console.log('url,req', url, req);
return fetch(url, req).then(handleResponse).catch(handleErrors);
}
And Add below line below Rest Controller class
@RestController
@CrossOrigin(origins = "*", allowedHeaders = "*")
class TestController{}