Since you already have the direct .mp4 URL from the Twitter CDN, adding a download button on your page is pretty straightforward using plain HTML.

Here’s a simple way to do it:

<a href="https://video.twimg.com/ext_tw_video/1735368028454567940/pu/vid/avc1/720x1280/K1xz9gR_dzGv3ad2.mp4?tag=12" download>
  <button>Download Video</button>
</a>

This will prompt the browser to download the video when the user clicks the button.
The download attribute in the <a> tag is what tells the browser to treat it as a file download rather than opening it.

If you're dynamically fetching the video URL via JavaScript, you can also set the href of the <a> element with JS.

Let me know if you're working with a framework or want to trigger this with a custom player!
You can check my work on https://twvideodownloader.net/ website i develop this tool.

Thanks