# Holding a Video Conference with WebRTC The **Web** component can start a camera and microphone by calling the W3C Standards-compliant API **navigator.mediaDevices.getUserMedia()** in JavaScript, and receive the permission request notification through [onPermissionRequest](../reference/apis-arkweb/ts-basic-components-web.md#onpermissionrequest9). To call these APIs, you need to declare the audio permissions in the **module.json5** file. - For details about how to add audio permissions, see [Declaring Permissions](../security/AccessToken/declare-permissions.md). ``` "requestPermissions":[ { "name" : "ohos.permission.CAMERA" }, { "name" : "ohos.permission.MICROPHONE" } ] ``` The **constraints** parameter in the API is a **MediaStreamConstraints** object that specifies the types of media to request. It contains two members: **video** and **audio**. In the following example, when a user clicks the button for enabling the camera on the frontend page and the **onConfirm** button, the **Web** component starts the camera and microphone. - Application code: ```ts // xxx.ets import { webview } from '@kit.ArkWeb'; import { BusinessError } from '@kit.BasicServicesKit'; import { abilityAccessCtrl } from '@kit.AbilityKit'; @Entry @Component struct WebComponent { controller: webview.WebviewController = new webview.WebviewController() aboutToAppear() { // Enable web frontend page debugging. webview.WebviewController.setWebDebuggingAccess(true); let atManager = abilityAccessCtrl.createAtManager(); atManager.requestPermissionsFromUser(getContext(this), ['ohos.permission.CAMERA', 'ohos.permission.MICROPHONE']) .then((data) => { console.info('data:' + JSON.stringify(data)); console.info('data permissions:' + data.permissions); console.info('data authResults:' + data.authResults); }).catch((error: BusinessError) => { console.error(`Failed to request permissions from user. Code is ${error.code}, message is ${error.message}`); }) } aboutToAppear() { // Obtain the permission request notification. After the onConfirm button is clicked, the camera and microphone are started. webview.WebviewController.setWebDebuggingAccess(true); let atManager = abilityAccessCtrl.createAtManager(); atManager.requestPermissionsFromUser(getContext(this), ['ohos.permission.CAMERA', 'ohos.permission.MICROPHONE']) .then(data => { let result: Array = data.authResults; let hasPermissions1 = true; result.forEach(item => { if (item === -1) { hasPermissions1 = false; } }) if (hasPermissions1) { console.info("hasPermissions1"); } else { console.info(" not hasPermissions1"); } }).catch(() => { return; }); } build() { Column() { Web({ src: $rawfile('index.html'), controller: this.controller }) .onPermissionRequest((event) => { if (event) { AlertDialog.show({ title: 'title', message: 'text', primaryButton: { value: 'deny', action: () => { event.request.deny(); } }, secondaryButton: { value: 'onConfirm', action: () => { event.request.grant(event.request.getAccessibleResource()); } }, cancel: () => { event.request.deny(); } }) } }) } } } ``` - Code of the **index.html** page: ```html

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