ModuleNotFoundError: No module named 'psutil'

[Eric-Sparks]

When trying to start ZephyrGate I get the following error:

$ ./start.sh 
Starting ZephyrGate...
ZephyrGate is starting...
Press Ctrl+C to stop

Traceback (most recent call last):
  File "/home/user/meshtastic-ZephyrGate/src/main.py", line 23, in <module>
    from core.health_monitor import HealthMonitor, HealthAlert, AlertSeverity
  File "/home/user/meshtastic-ZephyrGate/src/core/health_monitor.py", line 14, in <module>
    import psutil
ModuleNotFoundError: No module named 'psutil'

I have verifed that python3-psutil is installed. What am I missing?