Put relevant lines in the rfm file.
ParcFerme = 0 (set to 1 to switch on the below parc ferme conditions i.e for any of the following lines to work)
ParcFermeFuel = 0
// Whether fuel level remains the same (only if parc ferme is applicable). In general, this value specifies what fraction of the qualifying session is reached before fuel usage becomes "free"; default=0.0, possible values are 0.0-1.0, where 0.0 indicates fuel level is always free, 0.5 would mean fuel level at the halfway point of qualifying will be used to start the race, and 1.0 means fuel level at the end of qualifying will be used to start the race (and no refueling allowed during qualifying).
ParcFermeTires = 0 (Change this number to the number of qualifiers that will keep their used tyres to start the race)
ParcFermeSetup = 0 (set to 1 to force qual setup to be used in race)