To allow users to upload multiple files in an Angular application, you can use the input element with the multiple attribute.

Here is an example of how you might implement file upload in an Angular component:

import {Component} from '@angular/core';

@Component({
    selector: 'app-file-upload',
    template: `
    <form>
      <input type="file" name="files" (change)="upload($event)" multiple>
      <button type="submit">Upload</button>
    </form>
  `,
})
export class FileUploadComponent {
    constructor() {
    }

    upload(event) {
        const files = event.target.files;
        console.log(files);
        // handle file upload here
    }
}

In this example, we use the input element with the type attribute set to “file” and the multiple attribute to allow users to select multiple files. The change event is used to trigger the upload method when the user selects the files. The files property of the event.target object contains the selected files.

You can then handle the file upload process in the upload method. This might involve sending the files to a backend API using an HTTP client like HttpClient, or storing the files in a file storage service like Amazon S3.

For more information on file upload in Angular, you can refer to the Angular documentation at https://angular.io/guide/http.