Diagnosis
The igniter sparks but the gas valve isn't opening. The solenoid on the gas valve isn't getting power.
How to Fix It
First, check the 9V battery in the igniter module. It's under the front panel. Replace it. If that's good, check the wiring harness connection to the gas valve solenoid. It's a white plug. Unplug it, clean the contacts, reconnect firmly. Try again.
If That Didn't Work
The low-pressure regulator might be in bypass mode. Turn all knobs to OFF. Disconnect the propane tank hose. Wait 30 seconds. Reconnect the hose slowly, then open the tank valve slowly. Wait another 30 seconds before trying to light.
Heads Up
Never try to manually light this griddle. The air fryer burners are in an enclosed cavity. You'll cause a gas buildup and flashback.