Consequently, the video you are watching on Nitter is not hosted on Nitter’s permanent storage; it is being streamed directly from Twitter’s content delivery network (CDN). Because of this, Nitter itself does not have a built-in export feature. To download the video, you must capture the direct video link that Nitter is pulling.
A Step-by-Step Guide to Downloading Nitter Videos: Unlocking the Power of Twitter Video Content download nitter video
Several browser extensions (available for Firefox and Chrome derivatives) can detect videos playing on a webpage. Consequently, the video you are watching on Nitter