What version are you running ?
cat /etc/dogtag
I currently have BeagleBoard.org Debian Buster IoT Image 2020-04-06
on the nearest BBB to hand and that files does exist.
If you don’t have it by default, maybe the version you are running is too old.
I suppose also at some point it might have been made into an optional package that you need to install.
@RobertCNelson Will probably be able to tell you for sure when he sees your post.