Usually holding the button in creates a spark, which then ignites the fuel. If no ignition, wait a few minutes, listen for the safety switch to reset before attempting to light again.
Can you hear the spark?
Sometimes it helps to light a stove burner and run it for a few minutes so that there is LPG in the lines. If the rig has not been used in a while, the line might have air in it so even a good spark will not ignite it.
If still no luck, add the frig make and model to your next post so we can look for online owner's manuals.
