
It's no different from installing any browser extension. In the Download section, click Get from Store or whatever the relevant button is labeled, and then follow the onscreen instructions to install the extension.
Select the browser you're using from the bar of tabs along the top (choose Chrome for Brave or other Chromium-based browsers). Tampermonkey is an extension that allows you to customize and enhance the performance of websites. It officially supports Chrome, Microsoft Edge, Safari, Opera Next, and Firefox, but we tested it on Brave and it worked just fine there, too. You just need to be using a desktop browser. The best way to bypass age restrictions on YouTube is to install the Tampermonkey browser extension along with a script called "Simple YouTube Age Restriction Bypass". We've left all the old methods here for reference, and you can try them if you need to, although they're unlikely to work anymore.
The ones in this article are listed in order of their likelihood of working, so #1 is your best bet. Download YouTube Downloader Pro for Windows to download and convert videos from YouTube, Facebook, and thousands of other video sites.
Google frequently blocks new methods of bypassing age restrictions on YouTube. YouTube Downloader Pro has had 1 update within the past 6 months.