It’s a TikTok trend, not Instagram. In your video, you see the TikTok user name of “fonsecamargo”.
Go to the TikTok app & type or copy that name in the search function. The exact video popped up for me.
Similar videos use the same sound track. So, click on the slow spinning disc in the lower right corner. The original sound appears & shows nearly 15,000 videos created using that same sound.
You’ll go nuts when typing in “longhaircheck”… & following the sound… 97k videos.