When trying to run pkg bootstrap on an aarch64 system, the command fails as follows:
Bootstrapping pkg from pkg+http://pkg.FreeBSD.org/FreeBSD:13:aarch64/quarterly, please wait...
Signature for pkg not available.
pkg: Error fetching http://pkg.FreeBSD.org/FreeBSD:13:aarch64/quarterly/Latest/pkg.txz.sig: Not Found
A pre-built version of pkg could not be found for your system.
Consider changing PACKAGESITE or installing it from ports: 'ports-mgmt/pkg'.
The underlying cause seems to be a missing signature file for pkg.txz on at least this architecture.