The gas supply is not open.
Open the gas supply.

The burner does not ignite when the barbecue is being used for the first time, after it has been out of use for a prolonged period or after multiple attempts.
Open the gas supply.
Try to light the burner again, making several attempts if necessary.
Replace the gas bottle or have it refilled.
Close the gas supply immediately.
Carry out a leak test.
Contact Miele Customer Service.
Insert the burner correctly.
Clean and dry the burner.
Clean and dry the flame openings.