kc-react-config.js

import Keycloak from 'keycloak-js';

let initOptions = {
  url: 'http://localhost:8080/',
  realm: 'master',
  clientId: 'react-client',
  onLoad: 'check-sso', // check-sso | login-required
  KeycloakResponseType: 'code',
}

let kc = new Keycloak(initOptions);

kc.init({
  onLoad: initOptions.onLoad,
  KeycloakResponseType: 'code',
  silentCheckSsoRedirectUri: window.location.origin + "/silent-check-sso.html", 
  checkLoginIframe: false,
  pkceMethod: 'S256'
}).then((auth) => {
  if (!auth) {
    window.location.reload();
  } else {
    console.info("Authenticated");
    console.log('auth', auth)
    console.log('Keycloak', kc)
    kc.onTokenExpired = () => {
      console.log('token expired')
    }
  }
}, () => {
  console.error("Authenticated Failed");
});