Sure Heat Sonoma PFSISLP - Manual (Page 13)

Grill Assembly
STEP 11 - Rest the side burner grates into the right chamber.
Side burner
grates
13
STEP 12 - Unscrew the igniter push button cap and feed the "AA" battery into the igniter module
with the Positive (+) end facing out. Screw the cap back into place on the igniter module.
Igniter Push
Button