chrome-extensions-samples/api-samples/webRequest/http-auth/service-worker.js

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Provides credentials when an HTTP Basic Auth request is received.
chrome.webRequest.onAuthRequired.addListener(
  (details, callback) => {
    console.log('An authorization request has been detected');
    if (details.url == 'https://httpbin.org/basic-auth/guest/guest') {
      // Creating some credentials
      const username = 'guest';
      const password = 'guest';
      // Creating an auth handler to use the credentials
      const authCredentials = {
        authCredentials: {
          username: username,
          password: password
        }
      };
      callback(authCredentials);
    }
  },
  { urls: ['https://httpbin.org/basic-auth/guest/guest'] },
  ['asyncBlocking']
);