requestPermission（）：Promise<Permission>

请求发送通知的权限。

例

import { isPermissionGranted, requestPermission } from '@tauri-apps/api/notification';
let permissionGranted = await isPermissionGranted();
if (!permissionGranted) {
  const permission = await requestPermission();
  permissionGranted = permission === 'granted';
}

Since: 1.0.0

Returns: ​Promise​<​Permission​>

解决用户是否授予权限的承诺。