Are you using the NEST app or the Google Home app?
Here is a link that tells you how to do it for each app. HINT: If you are using the Google Home app then this procedure shows you had to save it to your phone's photos and you have to send the clip to someone from there using the various way your phone lets you send any video clip.
If you are using the older NEST app (which only works with the cameras sold before 9/2021) then there is a much nicer and easier way to do it.
Click here for instructions
https://support.google.com/googlenest/answer/9207572?hl=en#zippy=%2Cdownload-a-video-clip
Hope this helps.
