Here's IMDb's plot summary for Do Not Reply (2019):
"Chelsea, a teenager, is abducted through a social media app by Brad and is held captive with other girls who are to become victims in his virtual reality filmed murders."
That about sums the film up, but it's worth noting that Brad, like Glass' (2019) Kevin Wendell Crumb, has a high school cheerleader fetish, and he appears to be in his mid to late twenties.
The film's ending may be its most intriguing part. Minutes before Do Not Reply (2019) ends, two 13-year-old nymphets attempt to meet a "cute" 17-year-old boy via a social media app.
However, it doesn't matter. IRL, the 17-year-old, at a minimum, would have, like Ansel Elgort, been (incorrectly) called a pedophile. And at a maximum, he would have served jail time and had to register as a sex offender. And the nubile nymphets? Innocent. Not even a proverbial slap on the wrists.