Its documented. If you just type `podman-compose` in the command line you get...
usage: podman-compose [-h] [-v] [--in-pod in_pod] [--pod-args pod_args]
[--env-file env_file] [-f file] [-p PROJECT_NAME]
[--podman-path PODMAN_PATH] [--podman-args args]
[--podman-pull-args args] [--podman-push-args args]
[--podman-build-args args] [--podman-inspect-args args]
[--podman-run-args args] [--podman-start-args args]
[--podman-stop-args args] [--podman-rm-args args]
[--podman-volume-args args] [--no-ansi] [--no-cleanup]
[--dry-run]
{help,version,wait,systemd,pull,push,build,up,down,ps,run,exec,start,stop,restart,logs,config,port,pause,unpause,kill}
...
command:
{help,version,wait,systemd,pull,push,build,up,down,ps,run,exec,start,stop,restart,logs,config,port,pause,unpause,kill}
...
systemd create systemd unit file and register its compose stacks
When first installed type `sudo podman-compose systemd -a create-unit`
later you can add a compose stack by running `podman-compose systemd -a register`
then you can start/stop your stack with `systemctl --user start podman-compose@<PROJ>`