Hello
You can check the source code of the Instagram video page and extract the download link to download the videos from Instagram onto your computer.
Step 1. Open the Instagram video that you want to save, then right-click on it and select "Inspect element" (or "View page source" depending on your browser).
inspect element of instagram video
Step 2. Then press "Ctrl" + "F" keys on keyboard to open Find feature, and enter ".mp4" into the blank. Then the search will open a section of code.
Step 3. Then copy the link next to "src=" and the link ends with ".mp4", and paste the download link to a new tab. Then the video will start to play.
copy instagram video download link
Step 4. Now you can right-click on the video and select "Save video as..." option to download the video on your computer right now.
i hope it helps