Use Fiddler to download the video in the video number
1. Install Fiddler
2. Tools -> Options..-> HTTPS-> 
(this step is very important)
3. ctrl+x clears all captures on the left, it doesn’t matter if you don’t clear them
4. F12 appears in the lower left corner 
, if not, press F12 again
5. Open the video number forwarded to WeChat and wait for the end of the playback
6. Find the line whose Content-Type is vido/mp4. The icon on the left is 
, click to select, ctrl+U to copy the address to download
Fiddler
Download address: Link: https://pan.baidu.com/s/1ZJ2s8tihujwB0SbNkS1Yng?pwd=6saj
Note: If you use other proxy on the Internet, please close it, because Fiddler uses 127.0.0.1:8888 proxy