This is a bug in version 0.58 of OdooPBX. A fix should be available soon.

To work around this bug, first check the full path of odoopbx executable:

which odoopbx

You should get a full path, like /usr/local/bin/odoopbx

Then edit the service file at /etc/systemd/system/odoopbx-agent.service and change the line that starts with ExecStart to include the full path to odoopbx executable. An example is shown below:

From:
ExecStart=odoopbx run agent

To:
ExecStart=/usr/local/bin/odoopbx run agent

Save the file and run `systemctl daemon-reload` to apply the changes.