py command not present on Rocky Linux

[spartan782]

The following fails on Rocky because py is not a recognized command.

rock-createiso/master-iso.sh

Line 243 in f1f6bec

py 'jinja2.Template(open("templates/isolinux.cfg.j2").read()).render(json.loads(sys.stdin.read()))' | \

rock-createiso/master-iso.sh

Line 247 in f1f6bec

py 'jinja2.Template(open("templates/grub.cfg.j2").read()).render(json.loads(sys.stdin.read()))' | \

rock-createiso/master-iso.sh

Line 251 in f1f6bec

py 'jinja2.Template(open("templates/os-release.j2").read()).render(json.loads(sys.stdin.read()))' | \

rock-createiso/master-iso.sh

Line 255 in f1f6bec

py 'jinja2.Template(open("templates/buildstamp.j2").read()).render(json.loads(sys.stdin.read()))' | \

I tried locally updating the command to python3 but the script errors out with a file not found.

[spartan782]

Solvable by installing python3-jinja2 or creating a virtual environment and installing jinja2-cli.