1. Install the Ionic framework and Angular by running the following command:

   npm install -g @ionic/cli @angular/cli
   

2. Create a new Ionic project using the Angular framework by running the following command:

   ionic start my-youtube-downloader --type=angular
   

3. Navigate to the project directory and install the required dependencies:

   cd my-youtube-downloader
   npm install
   

4. Next, you'll need to find a way to download YouTube videos. One way to do this is by using the youtube-dl library, which you can install by running the following command:

npm install youtube-dl

1. In your Angular component, you can then use the youtube-dl library to download a YouTube video by calling the exec function and passing in the URL of the video you want to download. For example:

import * as ytdl from 'youtube-dl';

downloadVideo() {
  ytdl.exec('https://www.youtube.com/watch?v=videoId', ['-f', 'best'], {}, function(err, output) {
    if (err) throw err;
    console.log(output.join('\n'));
  });
}

1. You can then use the Ionic framework's UI components to create a user interface for your YouTube downloader. For example, you can use an Ionic input field to allow the user to enter the URL of the video they want to download, and a button to trigger the download process.

2. Finally, you'll need to handle the actual download of the video file. One way to do this is by using the download attribute of the a element, which allows you to specify a file to download and its name. You can use this attribute to initiate the download of the video file once it has been downloaded using the youtube-dl library.

   I hope this helps! Let me know if you have any questions.