Depends on the name of the cooker as to the details....
On the original Bavaria badged Techimpex cooker, the burners are made of cast iron and retained in place by a steel screw. If possible, remove the screw and clean the holes in the burner. They’re often slightly blocked by rust or baked on cooking debris. Use an appropriately sized screw driver or drill bit. Do be careful doing this as if you sheer the retaining screw you’ll have to drill out the remains of the screw and retap the hole. It can be done but it’s not easy (don’t ask how I know...).
Other makes of cooker don’t have the burner retained by a screw; you can simply lift the flame spreader cap and burner ring off the fitting and clean them. Note that the cap is made of cast iron and over time rusts away to the extent that it’ll need replacement. I’ve found on our Eno cooker that using a small triangular file on the burner removes any corrosion or burnt debris restoring normal function.