Facebook likes to keep your content on its service and doesn’t offer any way to natively download videos. So, while you can share Facebook video posts within Facebook or provide a link to the video, there is no to share that video via email or other social platforms.
However, there are still ways on how to download Facebook videos.
How to Download Facebook videos?
Step 1. On your computer, browse to the Facebook video that you want to download.
Step 2. In the upper right corner of the video post, click on the triple dots to reveal the menu.
Step 3. Click on Copy Link.
Step 4. Browse to https://www.getfvid.com/. Paste the copied link to the box and then click Download.
Step 5. Choose among the different options: “Download in HD quality,” “Download in Normal Quality,” and “Audio Only.” Select the video quality you want.
Step 6. A new tab will open and play the video that you want to download. In the lower right corner of the video click on the triple dots. Select Download and the video will now be downloaded.
Sources:
https://www.techlicious.com/tip/how-to-download-video-from-facebook/