Shell script will not run from HA Script or Automation

Hassio (KVM VM)
Core: 2021.8.6
Supervisor: 2021.06.8
OS: Home Assistant OS 6.2

Is it possible to run shell scrips in HA (hassio)? Is that a permission issue?

I have a simple shell script which checks ping results. This script works in the shell environment but will not start from GUI.

That was a wrong path to the script output file (with the ping results). It works now.